Would someone please describe the correct (if any) markings a preban Colt, blue label HBar 20" flattop upper receiver should have?
Looks correct with A2 flattop receiver, correct CMP full HBar Colt 1:9 barrel, A2 flash suppressor, no bayo lug, small front pivot hole. No receiver vise/wrench marks or vise/wrench marks on the barrel. Seller states the upper came as complete rifle - flattop preban all-Colt.
I just purchased an upper minus charging handle, carry handle, and bolt/carrier assembly. The upper looks to be of good Colt-type quality, but I can only find 2 small (like 3/8" size) markings below and slightly in front of the ejection port. Color looks like the correct Colt black. I thought all Colt uppers had some markings, like CM or CAF, but I remember reading that some of the earlier flat tops did not.
I can take a digital pic and post if it will help.
Can anyone shed some light on this for me? Any help is appreciated.