Well, not sure what it's officially called, but after 23 years of use, I like to refer to the finish on mine as "Crappy Looking"!
Seriously though, to me the so "called poly" coat on mine looks just like Tremclad - thick and glossy. Only one difference though: apparently it chips pretty bad!
I just picked up this '84 vintage Pre-B and got it for a good price, 'cause apparently the previous owners weren't very careful with the finish. Shoots like a dream though - I love everything about it but the finish...
I'd really like to clean it up and get it blued, but I'm afraid that would cost more than the gun is worth...
TFC