I've thought about this quite a bit Bill. The barrel is awfully small for a solid rib and it would have to be considerably scaled down from shotgun size.

Likewise the stock is very small and proportions would be tricky. The Owen Remington gives an idea of the challenge, the stock almost looks too big for the action. And, what to do with the tiny for end??

I would spend considerable time on paper before I made any decisions.

I've got a 61 and they are even more fun to shoot than a 39A. Both are stupid accurate at iron sight ranges.
All, IMO...