Waltham 1894 Model, Grade 220

This Waltham watch is one of several that are odd sizes. Either the diameter, or the thickness, of the movements, or both, are unusual requiring them to have exactly the Waltham case that they were sold with originally. For bare movements, matching them to cases is almost impossible.

This one is a little larger than a 12 size, but it also has a ring added to the base plate making it larger. The ring is held on by an extra set of screws that look like the dial screws, going into the edge of the plate. With this ring in place, the movement still isn't a standard size. It's just a little smaller than 16.

Here are some details on the Waltham setting/winding mechanism - quite different from the Elgin designs.

Note how the arbor does not reach the outside edge of the base plate expansion ring.

I have seen a few Walthams, and at least one Elgin, with the base place expanded or stretched to step up the size a notch. It seems like a complicated thing to do, but perhaps the larger sizes were betting sellers.