I don't think the tension assembly changed from the smaller to larger machines. Comparing different models, like the 201, 66, 99, and even the Featherweight from about the same period, the tensions look extremely similar. I think most of the parts would be interchangeable if you needed. It's just that the older style Singer tension didn't have the numbered dial, so that added a few pieces to the newer style.
I'm still curious to know whether they would be difficult to switch out.
