Researcher’s eye is good. Tamid’s gun is odd. The etched engraving is common to the 400 and 500 serial range A and B guns, but the lock work is of a later type. I’d guess , like we find with Lefevers, an early serial number gun can have late serial number details. I assume Baker used up what materials they had around in stock, not necessarily trying to strictly follow a serial number sequence. Tamid’s gun is an A Grade and quite nice.

http://www.bakercollectors.com/