The loco I have is numbered #5205 and has a six wheel tender significantly longer than the six-wheel tender fitted to my K Line and Lionel semi-Scale Hudsons. So, it seems consistent with your description.
I did struggle with the whole scale/semi-scale thing, to begin with.
So.. my K Line loco has compressed dimensions (length) and good detail, and a short tender, so it’s semi-Scale. The MPC era Lionel one is the same size, with MPC era detail, so it’s semi-Scale.
The Williams loco is scale length, with a scale length tender. It originally came with small front wheels. Its drivers are visibly larger than either of the other locos. It has detail best described as “Post War Level”. So I’m going with “scale length” for that one. On that basis, I went with the 17mm wheels in the original pilot frame, so as to improve the appearance without unduly compromising the minimum radius.
