Jeff- on the first one of your Parkers shown- I believe i can just barely see a pin where they staked the filler piece into the milled area of the receiver- very nice bit of machining-betcha you can't take a common pin and fit it in anywhere around the filler at the juncture-
Don't mean to be picky, but I believe we mean to say "Forged" or actually, drop forged, and not cast. I have a older 12 gauge receiver from a Crescent hammer gun, it was cast with the cope and drag method of the day, and either spark test of file tests verify that, as well as the visible grain structure in the areas milled to dim. It is a fine paperweight, and if it were from an 8 gauge Crescent, might even qualify as a boat anchor-
Any 12 bore side-by-side used for live birds, whether box or Columbaire, has to be a "top shelf" shotgun, just as I have read that the great cane rodmakers of the past really stepped up when they built a salmon rod.
Will you use this DHE on pigeons- the real ones that explode into a cloud of feathers, and not into black and blaze orange powder? I hope so!!