If it's convenient for you, dump any data you have on maps - tilesets, map grids, city data, event scripting, and how to determine what is text (pointers? opcodes with range parameters?) as I remember it's compressed.
If anyone has any interesting hacks/mods which do cool things like add in content from the PS1 or Saturn versions, archive those for later perusal in case we can diff them against a vanilla rom and rule out known data to isolate changes. I think Zombero has a few interesting hacks where he made a resistance view in the menu, expanded the number of classes, and maybe dehardcoded a few things. I know finshore did a few dehardcoding hacks, as did I think Faustwolf - or was that palettes?