trying to buy fenders.....again..

[79 blue monster]

i've had alot of bad luck with trying to buy fenders for my pick up. i got srewed over by people with aftermarket that said they were gm. all garbage. i learned that you can tell if their gm by looking on the pinch weld for the GM stamp. i found a guy that went to montana and bught a cab and front clip. i want to make sure the fenders are gm. they are not stamped gm on the pinch weld, but also dont have a made in tiwann stamp on the inside either. the fenders have some little clues on them, trim holes blocked off, original emblems mounted, little repaind, original fading green paint like the rest of the truck..etc i need your guys help to deternin if their gm or not. i did find a symbol on the front inside of the fender(pictured).