Beretta 424 Series
They were introduced in 1950, and are still produced. The breech is forged from a single piece of nickel steel.
The Model 427 has hand-engraved side plates for the breech block that made to order.
For most of its production time, these shotguns were made with a choice of single or double triggers, but they are now made only with single triggers, and the safety catch doubles as a barrel selector.
Models 426E and 427 have automatic ejectors; Model 424 has a manual extractor.
http://www.gunbroker.com/Auction/ViewItem.aspx?Item=386050374