--- a/projects/openttd_vs100.vcxproj
+++ b/projects/openttd_vs100.vcxproj
@@ -724,6 +724,7 @@
     <ClCompile Include="..\src\saveload\map_sl.cpp" />
     <ClCompile Include="..\src\saveload\misc_sl.cpp" />
     <ClCompile Include="..\src\saveload\newgrf_sl.cpp" />
+    <ClInclude Include="..\src\saveload\newgrf_sl.h" />
     <ClCompile Include="..\src\saveload\oldloader.cpp" />
     <ClInclude Include="..\src\saveload\oldloader.h" />
     <ClCompile Include="..\src\saveload\oldloader_sl.cpp" />

--- a/projects/openttd_vs100.vcxproj.filters
+++ b/projects/openttd_vs100.vcxproj.filters
@@ -1375,6 +1375,9 @@
     <ClCompile Include="..\src\saveload\newgrf_sl.cpp">
       <Filter>Save/Load handlers</Filter>
     </ClCompile>
+    <ClInclude Include="..\src\saveload\newgrf_sl.h">
+      <Filter>Save/Load handlers</Filter>
+    </ClInclude>
     <ClCompile Include="..\src\saveload\oldloader.cpp">
       <Filter>Save/Load handlers</Filter>
     </ClCompile>

--- a/projects/openttd_vs80.vcproj
+++ b/projects/openttd_vs80.vcproj
@@ -2184,6 +2184,10 @@
 				>
 			</File>
 			<File
+				RelativePath=".\..\src\saveload\newgrf_sl.h"
+				>
+			</File>
+			<File
 				RelativePath=".\..\src\saveload\oldloader.cpp"
 				>
 			</File>

--- a/projects/openttd_vs90.vcproj
+++ b/projects/openttd_vs90.vcproj
@@ -2181,6 +2181,10 @@
 				>
 			</File>
 			<File
+				RelativePath=".\..\src\saveload\newgrf_sl.h"
+				>
+			</File>
+			<File
 				RelativePath=".\..\src\saveload\oldloader.cpp"
 				>
 			</File>

--- a/source.list
+++ b/source.list
@@ -475,6 +475,7 @@
 saveload/map_sl.cpp
 saveload/misc_sl.cpp
 saveload/newgrf_sl.cpp
+saveload/newgrf_sl.h
 saveload/oldloader.cpp
 saveload/oldloader.h
 saveload/oldloader_sl.cpp

--- a/src/saveload/airport_sl.cpp
+++ b/src/saveload/airport_sl.cpp
@@ -10,45 +10,18 @@
 /** @file airport_sl.cpp Code handling saving and loading airport ids */
 
 #include "../stdafx.h"
-#include "../newgrf_commons.h"
 
 #include "saveload.h"
-
-/**
- * Save and load the mapping between the airport id in the AirportSpec array
- * and the grf file it came from.
- */
-static const SaveLoad _airport_id_mapping_desc[] = {
-	SLE_VAR(EntityIDMapping, grfid,         SLE_UINT32),
-	SLE_VAR(EntityIDMapping, entity_id,     SLE_UINT8),
-	SLE_VAR(EntityIDMapping, substitute_id, SLE_UINT8),
-	SLE_END()
-};
+#include "newgrf_sl.h"
 
 static void Save_APID()
 {
-	uint i;
-	uint j = _airport_mngr.GetMaxMapping();
-
-	for (i = 0; i < j; i++) {
-		SlSetArrayIndex(i);
-		SlObject(&_airport_mngr.mapping_ID[i], _airport_id_mapping_desc);
-	}
+	Save_NewGRFMapping(_airport_mngr);
 }
 
 static void Load_APID()
 {
-	/* clear the current mapping stored.
-	 * This will create the manager if ever it is not yet done */
-	_airport_mngr.ResetMapping();
-
-	uint max_id = _airport_mngr.GetMaxMapping();
-
-	int index;
-	while ((index = SlIterateArray()) != -1) {
-		if ((uint)index >= max_id) break;
-		SlObject(&_airport_mngr.mapping_ID[index], _airport_id_mapping_desc);
-	}
+	Load_NewGRFMapping(_airport_mngr);
 }
 
 extern const ChunkHandler _airport_chunk_handlers[] = {

--- a/src/saveload/industry_sl.cpp
+++ b/src/saveload/industry_sl.cpp
@@ -11,9 +11,9 @@
 
 #include "../stdafx.h"
 #include "../industry.h"
-#include "../newgrf_commons.h"
 
 #include "saveload.h"
+#include "newgrf_sl.h"
 
 static const SaveLoad _industry_desc[] = {
 	SLE_CONDVAR(Industry, location.tile,              SLE_FILE_U16 | SLE_VAR_U32,  0, 5),
@@ -71,35 +71,14 @@
 	}
 }
 
-/* Save and load the mapping between the industry/tile id on the map, and the grf file
- * it came from. */
-static const SaveLoad _industries_id_mapping_desc[] = {
-	SLE_VAR(EntityIDMapping, grfid,         SLE_UINT32),
-	SLE_VAR(EntityIDMapping, entity_id,     SLE_UINT8),
-	SLE_VAR(EntityIDMapping, substitute_id, SLE_UINT8),
-	SLE_END()
-};
-
 static void Save_IIDS()
 {
-	uint i;
-	uint j = _industry_mngr.GetMaxMapping();
-
-	for (i = 0; i < j; i++) {
-		SlSetArrayIndex(i);
-		SlObject(&_industry_mngr.mapping_ID[i], _industries_id_mapping_desc);
-	}
+	Save_NewGRFMapping(_industry_mngr);
 }
 
 static void Save_TIDS()
 {
-	uint i;
-	uint j = _industile_mngr.GetMaxMapping();
-
-	for (i = 0; i < j; i++) {
-		SlSetArrayIndex(i);
-		SlObject(&_industile_mngr.mapping_ID[i], _industries_id_mapping_desc);
-	}
+	Save_NewGRFMapping(_industile_mngr);
 }
 
 static void Load_INDY()
@@ -117,38 +96,12 @@
 
 static void Load_IIDS()
 {
-	int index;
-	uint max_id;
-
-	/* clear the current mapping stored.
-	 * This will create the manager if ever it is not yet done */
-	_industry_mngr.ResetMapping();
-
-	/* get boundary for the temporary map loader NUM_INDUSTRYTYPES? */
-	max_id = _industry_mngr.GetMaxMapping();
-
-	while ((index = SlIterateArray()) != -1) {
-		if ((uint)index >= max_id) break;
-		SlObject(&_industry_mngr.mapping_ID[index], _industries_id_mapping_desc);
-	}
+	Load_NewGRFMapping(_industry_mngr);
 }
 
 static void Load_TIDS()
 {
-	int index;
-	uint max_id;
-
-	/* clear the current mapping stored.
-	 * This will create the manager if ever it is not yet done */
-	_industile_mngr.ResetMapping();
-
-	/* get boundary for the temporary map loader NUM_INDUSTILES? */
-	max_id = _industile_mngr.GetMaxMapping();
-
-	while ((index = SlIterateArray()) != -1) {
-		if ((uint)index >= max_id) break;
-		SlObject(&_industile_mngr.mapping_ID[index], _industries_id_mapping_desc);
-	}
+	Load_NewGRFMapping(_industile_mngr);
 }
 
 static void Ptrs_INDY()

--- a/src/saveload/newgrf_sl.cpp
+++ b/src/saveload/newgrf_sl.cpp
@@ -17,6 +17,39 @@
 #include "../fios.h"
 
 #include "saveload.h"
+#include "newgrf_sl.h"
+
+/** Save and load the mapping between a spec and the NewGRF it came from. */
+static const SaveLoad _newgrf_mapping_desc[] = {
+	SLE_VAR(EntityIDMapping, grfid,         SLE_UINT32),
+	SLE_VAR(EntityIDMapping, entity_id,     SLE_UINT8),
+	SLE_VAR(EntityIDMapping, substitute_id, SLE_UINT8),
+	SLE_END()
+};
+
+void Save_NewGRFMapping(const OverrideManagerBase &mapping)
+{
+	for (uint i = 0; i < mapping.GetMaxMapping(); i++) {
+		SlSetArrayIndex(i);
+		SlObject(&mapping.mapping_ID[i], _newgrf_mapping_desc);
+	}
+}
+
+void Load_NewGRFMapping(OverrideManagerBase &mapping)
+{
+	/* Clear the current mapping stored.
+	 * This will create the manager if ever it is not yet done */
+	mapping.ResetMapping();
+
+	uint max_id = mapping.GetMaxMapping();
+
+	int index;
+	while ((index = SlIterateArray()) != -1) {
+		if ((uint)index >= max_id) break;
+		SlObject(&mapping.mapping_ID[index], _newgrf_mapping_desc);
+	}
+}
+
 
 static const SaveLoad _grfconfig_desc[] = {
 	    SLE_STR(GRFConfig, filename,         SLE_STR,    0x40),

new file mode 100644
--- /dev/null
+++ b/src/saveload/newgrf_sl.h
@@ -0,0 +1,29 @@
+/* $Id$ */
+
+/*
+ * This file is part of OpenTTD.
+ * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
+ * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** @file newgrf_sl.h Code handling saving and loading of NewGRF mappings. */
+
+#ifndef SAVELOAD_NEWGRF_SL_H
+#define SAVELOAD_NEWGRF_SL_H
+
+#include "../newgrf_commons.h"
+
+/**
+ * Save a GRF ID + local id -> OpenTTD's id mapping.
+ * @param mapping The mapping to save.
+ */
+void Save_NewGRFMapping(const OverrideManagerBase &mapping);
+
+/**
+ * Load a GRF ID + local id -> OpenTTD's id mapping.
+ * @param mapping The mapping to load.
+ */
+void Load_NewGRFMapping(OverrideManagerBase &mapping);
+
+#endif /* SAVELOAD_NEWGRF_SL_H */

--- a/src/saveload/town_sl.cpp
+++ b/src/saveload/town_sl.cpp
@@ -11,10 +11,10 @@
 
 #include "../stdafx.h"
 #include "../newgrf_house.h"
-#include "../newgrf_commons.h"
 #include "../town.h"
 
 #include "saveload.h"
+#include "newgrf_sl.h"
 
 /**
  * Check and update town and house values.
@@ -139,36 +139,14 @@
 	SLE_END()
 };
 
-/* Save and load the mapping between the house id on the map, and the grf file
- * it came from. */
-static const SaveLoad _house_id_mapping_desc[] = {
-	SLE_VAR(EntityIDMapping, grfid,         SLE_UINT32),
-	SLE_VAR(EntityIDMapping, entity_id,     SLE_UINT8),
-	SLE_VAR(EntityIDMapping, substitute_id, SLE_UINT8),
-	SLE_END()
-};
-
-static void Save_HOUSEIDS()
+static void Save_HIDS()
 {
-	uint j = _house_mngr.GetMaxMapping();
-
-	for (uint i = 0; i < j; i++) {
-		SlSetArrayIndex(i);
-		SlObject(&_house_mngr.mapping_ID[i], _house_id_mapping_desc);
-	}
+	Save_NewGRFMapping(_house_mngr);
 }
 
-static void Load_HOUSEIDS()
+static void Load_HIDS()
 {
-	int index;
-
-	_house_mngr.ResetMapping();
-	uint max_id = _house_mngr.GetMaxMapping();
-
-	while ((index = SlIterateArray()) != -1) {
-		if ((uint)index >= max_id) break;
-		SlObject(&_house_mngr.mapping_ID[index], _house_id_mapping_desc);
-	}
+	Load_NewGRFMapping(_house_mngr);
 }
 
 static void Save_TOWN()
@@ -192,6 +170,6 @@
 }
 
 extern const ChunkHandler _town_chunk_handlers[] = {
-	{ 'HIDS', Save_HOUSEIDS, Load_HOUSEIDS, NULL, NULL, CH_ARRAY },
-	{ 'CITY', Save_TOWN,     Load_TOWN,     NULL, NULL, CH_ARRAY | CH_LAST},
+	{ 'HIDS', Save_HIDS, Load_HIDS, NULL, NULL, CH_ARRAY },
+	{ 'CITY', Save_TOWN, Load_TOWN, NULL, NULL, CH_ARRAY | CH_LAST},
 };