Thanks very much for the pics! I've seen a number of doubles chambered for rimless cartridges, and always wondered exactly how they ejected/extracted the cases. I would guess that rebated-rim carts, like the .425WR, would be particularly awkward to eject.
As for dangerous game use, that's a non-issue to me. Nobody's going to face a wounded buffalo/lion/elephant/sabre-toothed marmoset/etc. with a double in .30-06, or other similar rounds. That's just common sense.
Thanks again.