Geez, getting back onto this BBS was almost as tough as finding a front end for a 20 gauge Model 12. Now that I'm finally back in, I gotta contact Dave.

Browning Model 12 parts may work on your Win frame. I know a guy who mated a Browning Mod 42 front end to a Win 42 frame, and he now shoots a Brownchester for skeet. Seems to work just fine. There will probably be issues with the rib extension if your gun didn't originally have one.