Some very light OU's achieve that weight reduction by using an alloy receiver with a steel insert in the breech face. I don't think Beretta does that. My 687 28ga is all steel.

Replacement, you're right. I goofed on that one. The gun was imported and marketed by Sig, with some of them branded for LL Bean, but they were made by B. Rizzini. I think those Auroras are probably some of the better deals out there in OU's.