I think what you are trying to is you want 317 maps on a 525 client. Just repack 317 map models. Follow the index replacing tutorial if you haven't already.
http://www.rune-server.org/runescape...repacking.html
Then simply create a folder in your cache called index4 and put the zipped .dats in it. Then go to client.java (client sided) and search for preloadModels(); should be commented. Just type under that " repackCacheIndex(4); and run your client. It will repack 317 map data into your client. Make sure you remove the repackCacheIndex(4); and the index4 folder after you have repacked. If you need me to do this all for you just Skype me at Rhssoccer4. I won't be home for another 7 hours though.