Hello Sparkyflint:
Anybody can have a run of bad luck, and it sounds like you have with two used American SXS's failing the same day. Or you may not know enough yet to distinguish the thread-bare, poorly repaired, or low quality from the lightly used, well maintained or higher quality guns.
I not meaning to demean, only to relate that when I first got into doubles, just about anything on the used rack interested me... now I can faily quickly assess twenty to find the one that looks both higher quality and in better condition. And worn or low quality doubles tend to accumulate on shop racks.
I also had the advantage of having inherited a Parker VHE that my great grandfather purchased in 1915. It was hunted heavily until WWII for waterfowl and dove, and shot every season through the present for prairie birds and targets. I estimate I've personally put 2,000 rounds through it during the 15 years it has lived with me. It was slightly off face when I inherited it, both both bores still gauged full-and-full. However accidents do happen, and the buttstock was replaced when my own father cracked it as a teen. I know of a single mechanical failure with the gun, a leaf spring to the top lever cracked when I was in the middle of a dove hunt with it about 10 years ago. My great uncle swears it never had another repair done to it, besides annual lubrication. I've had it put back on face. Not bad for an American shotgun that has probably digested 20,000 rounds over the 97 years it has been in the family.
I'm sure others have similar stories about their American doubles which make mine pale in comparison....
Ben