Jim in VA, first off, welcome to the forum. Lots of smart folks here, and few smart ...., well you know.
You might be better served by posting this in the Semi-auto section. As for your question, I'm not sure if the 3913 slide will fit on your 3953 TSW frame. The 3913 is a single stack and the TSW, I believe, is a double stack, so there may be a width difference between the two frames. If you could try the slide on your frame to verify the fit first, that may get you part way to your goal. As far as any other changes, I don't believe any others are necessary. Others will no doubt correct me and talk badly behind my back if I have erred.
Good Luck and good shooting.