The TSWs had the slides hand fitted to the frames, the 457 was part of the value line. Rock the slides on both. The TSW will have very little movement, while you will be able to rock the slide side to side. The TSWs had much tighter tolerances, while the value line was mass produced. I have owned both and sold the 457 because it didn't shoot as well as my other 3rd gens. But I understand the want to keep the TSW as a safe queen, I am having the same problem with a 5946 NOS that I picked up. It is a hard call.