The ones I've come across have had 4 different foundry markings on the head. The most common are the letters TR or just R. No other marks, just the letters. Another has the letters WB on a slightly indented head, sorta looks like WB surrounded by a raised circle around the outer part of the head. And a fourth had no markings at all, probably just made its way through the forming process without getting stamped.
Then there are the #14 sheet metal screws, such as on the lower grill to splashpan and a couple of places on the hood latch to grill panel. They are just indented head.
It's common to have a mismatch here and there, when the assembly line worker was pulling bolts, he wasn't concerned if the markings were the same.When a bolt bin was getting low, they'd probably just call material control and dump another box full in.
Bob
