[Linked Image from i.imgur.com]

I agree with Argo44 that A&D patent use numbers are of little if any assistance in dating a gun. I think that they may have been allocated in blocks to different makers.

That raises the question, has anyone encountered a duplicate PUN on guns from different makers?

The Edwinson Green shown above, an early A&D with no bottom bolt probably dates from 1880 as its serial number is slightly below 2922 recorded when the surviving Edwinson Green records start in 1881