First, I want to thank everybody for their help. I am now certain the gun is a 409PB even though it is not marked as such (even under the foreend).
Following your post re what I now realize are choke numbers, both barrels are marked 15,8 which is .622 inches (20 ga.) and the left barrel is marked 15,0 (.591") and the right barrel is marked 15,5 (.610"); the barrels are "ALLOY CHROMIUM ELECTRIC STEEL SPECIAL TYPE AUSONIA" and I see the number "70" which appears to be the barrel length and K 1,180 (strength?).
Do those choke numbers correspond to MOD and FULL?
