David, you are correct up until recently the 20 gauge was the last known A2 produced. I purchased the 12 gauge A2 a few months ago. When I purchased it I was told it was a Monogram. Since that time with the help of Tom Archer, and James Stubbendieck I was able to determine it was an A2 and a search of the records found that it was indeed recorded as an A2. The gun was finished July 19, 1916. It is a 2 barrel set, although not recorded as such.