Since S&W has had nothing to do with the TPH, I'm not sure they would be particularly interested in servicing one.
The American-made TPHs unfortunately did not have a great reputation for reliability. They either worked perfectly or poorly, a very apt demonstration of what happens when factory QC is not maintained. Just as Walther/Umarex is learning now with the PPS, whatever initial testing has been done to bring a gun to market is not enough; problems with off-spec materials and drifting tolerances creep in during ongoing production (sometimes repeatedly), and unless inspection and test firing is kept up at close intervals, things can go to hell in a hurry.
I have a stainless TPH of later production that, fresh off the assembly line, was subjected to a 1,000 round functioning test in order to verify that certain production corrections were being maintained. Just prior to that, some guns were coming off the line that were not working properly. This one breezed through the test with less than 1/10th of 1% malfunctions from all causes-- which is less than the expected reliability of Remington rimfire ammunition. I bought that gun, but I would not trust any other that has not been similarly tested.
The German guns generally work well, but only in single-action. Often they misfire in double-action, and there is no easy fix.
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