Beretta shotgun??

I have a 12 ga. sxs, s/n 4xxx, 28" barrels, choked full&I/M. It is a boxlock, double triggers(the front trigger is spring loaded to fold forward under recoil). I was purchased in Germany in the early 1960's. The receiver is silver colored and heavily engraved in a flowery style with lots of scrollwork, there is a silver pigeon in flight on the blued release lever. Stock is top grade walnut with 18LPI checkering. It has sling mounts on the buttstock and under the barrels, forearm release is a plunger at the front. I cannot find anything exactly like it in the regular reference books. The 400 series and Silver Hawk are similar but the stock on mine has a rounded pistol grip vs flattened as for a grip cap.
Whatizzit? Thanks, Mike

Mike in Michigan