Starting in 1949 and running though the 1960s (and maybe later), Beretta made a line of boxlock over & under shotguns called the AS grades.
Most Beretta guys agree that they are the finest boxlock double barrel O/Us shotguns ever made by Beretta. They came in 12g and 20g and were offered in a handful of different grades and with a number of different options.
This is one of the more desirable grades & configurations: the ASEL 20 gauge. If you’re looking for a great O/U and you don’t mind a single trigger and pistol grip, it’s a great gun. Because it’s at auction, you may be able to get a good deal on it. I think $4000-$4500 is a fair price for this gun, so anything less than that is a good deal.
Here are couple of there ASELs on the market to compare this one to: a ASEL 12g and a real nice one in 20 gauge.
These are great guns. They have the more robust locking system found on the SO sidelocks and the current DT10s, and were hand finished to a much higher degree that Berettas current non-sidelock guns.
The only thin that kills it for me is sling swivels on the barrel and but of a lot of them. Must be a little bit of Germanic influence going on there