New better skins for the Colt 45, Knife, Uzi, Desert Eagle, AK-47 and MP5.
use GTASA ultimate editor (http://gtasamods.com/pafiledb.php?action=file&id=11)
or iripper (http://toca.game-editing.net/dl?f=iripper1.8b.zip)
to open up gta3.img under program files/rockstar games/gta san andreas/models
then do a 'find' for whichever weapon you wish to replace. this package comes with colt45, knifecur and mp5lng.
so pick whichever you like then search the given name. and be sure to find the .txd to replace, NOT the .dff.
if using iripper, select the .txd then on the left click 'replace file'. not sure about the ultimate editor...havent used it