I'm still deaf from that ported pugI think you went above and beyond and your reputation here speaks for itself.
I do have a personal story to add that's kinda funny. I bought a brand new Charter Arms .357 Pug, the first cylinder shot fine, and every cylinder after that locked up, just like the Colt you're dealing with. I sold it to a member who is in this thread with full disclosure. He told me he never had an issue with it, ever. So possibly it was the Blazer .38spl ammo I was running? Anyway, he had traded me a stainless Marlin Model 60 in the deal. I put several hundred rounds through it without a single hiccup. Later I traded that Marlin to someone else, who then posted it up for like $50 bc he said something was wrong with it and it wouldn't cycle. So sometimes the chain of events that make you shake your head are just gonna happen, all you can do is roll with it the best you can, it happens to the best of us.
I don't remember who I traded it too but never heard back from them, so I imagined it worked fine for them as well.