Dave,
Sorry to hear about that trouble. You hate to be the guy that gets a bad one. But, Id bet you would have a hard time finding another Beretta that did the same thing. I know there are guys here who believe Winchester 21s are tough, or durable, or, whatever, but, Ive seen or handled at least a dozen that had loose ribs or loops or both. I think if you want to avoid the problems that come with old guns, you might want to avoid old guns.
The Japanese Double you came into seems like a good start down that road.

Hey, best of luck.

Best,
Ted