Like was said the Westley records are only going to tell you that the gun was originally black proofed with choke. The "Pigeon gun" sounds good but it's just a selling a selling point. this gun is a long way from being a pigeon gun.

It's marked .740 I suspect that's the current bore diameter....meaning it had been honed from .719/.729 to .740. It's advertised at .736 meaning someone isn't measuring it right.

The 2 & 3/4", 850 bar would probably be the last proof...If it was I I'd keep looking.