And why gta3? You can modify from maps folder, with Med.
Like this picture?
Add some trees, park and something like that ...........
I can give my maps folder and you just to modify..
Ah, I can do that. Could you send me your maps folder in PM?
Ah dude, it's not only remove the cities with MEd or something. You do need to mod files so SF and LS dissapear, you need to mess another files so I can't do anything or the game would crash.
Try googling "Steve M's Map Cleaner" and clean SF and LV.
Example: Go to the building right in front of your Bohan one and climb the stairs until the last floor (Not the roof!) then look at the walls where's some blood and a weapon.
I think savegames from other people don't work due to achievement data. When I always tried other people's saves, it always says "Load Failed. Please check your HDD".