Good news, I now have the maps for the underground areas, as well as an even higher resolution world map. I believe i have every image from the game now, including some higher resolution versions of all unlock images, and logos of everything.
As it turns out, I had only extracted a third of the images, because they were stored in several different files.
It will take some time to sort through these 80,000 images to sort through, but once I've got them all sorted, I think I'll just upload them all here as soon as possible, so they can be added to articles immediately.
I've also found the co-ordinate files I was missing, which means there are even more maps I can generate now, including racing paths, and maps for other activities.
So much to do. :(
edit: okay, finally got rid of all the duplicates. I still haven't found the SR2 gravestones, so i guess they must be dynamic. edit: haha, it is now a few minutes after the text edit. I just found the gravestone file.