Please school me on IDing GM grill parts for 68

[Luwi67]

Hi guys,
I have a standard grill, bezels and upper/lower moldings and am having trouble deciphering if they are GM, GM service parts or, aftermarket reproduction.

The grill has numbers 3914772 stamped in the back bottom right hand side and just to the right of that there is UPP 88 025 stamped. Also a small white round sticker with "Made in Canada" around the circumference and a maple leaf in the center in red. That's all I can find on the center grill.




This was the "Made in Canada" sticker that came off when i washed the grill:


All I can find on the bezels is the letter N stamped in the lower outside corners.


I couldn't find any markings on the upper and lower moldings. Is there a certain place to look? Did GM stamp the moldings?

Does anyone know how to tell if these parts are GM.

I have the turn signal lights as well, how can i tell if those are GM, the only thing I found was "Made in USA" and an SAE number stamped on the housings.

Any help would be great, Thanks.