Did a search, nothing really answered my question.

Prepping my car to be repainted and pretty much knew from the way the driver fender lined up that it was aftermarket. Pulled it off and sure enough, made in Taiwan, replacement part.

My passenger fender fit perfect and on the inside has markings and lettering stating it was made in Canada, so I'm assuming it's genuine GM.

Is this the correct assumption?

I had planned on going to the junk yard to find another gm driver side, but had someone selling one local, however it has NO markings at all on the backside, not even aftermarket.

Are there any other distinguishing marks to ensure I'm not passing over gm fenders, or all they all labeled somewhere?