I never heard of such a thing.
I believe you're thinking of swapping a Rossi with a Cox Conquest, not a Tee Dee. That was done all the time. A simple slip fit, no machining required.
In those days, getting Cox parts was easy, Rossi, next to impossible. Just slipping in a Rossi pistone' y cylindre' sounded good until you tried to find one. I went the other way. I kept my two Rossi's going with Cox parts, until one blew a crank, which I could never replace.
By my observation, the Rossi was over-rated like a Ferrari, and the Cox was underated like a Corvette. People were conned into going to great lengths to pay $150 for a Rossi while you could get a Cox (just as good) for $40.
That whole issue was buried by Henry Nelson.