No offense, but they look compressed(I know they don't have Phong, or normals, or anything lol just Diffuse.)
But did you export the VTF as DXT5? Uncompressed is better for source, cause from the looks of it they look like photoshopped images from FPSC to Source(Getting a picture, cropping the gun, than overlaying it ontop of a image of source.)
(Oh, and you may wanna fix up the origins, there looks incredibly iffy... O.<, move them up by a little bit and more to the center. that way it'll be much, much realistic.)
Edit:
Actualy I can remember porting these to CS:S once... Lost the files but I might do it again.
"Your greatest teacher is your harshest critic"-'Butterfingers'