Slide 6: Wm. Ellery versus Home Watch Co. 

The closed Ellery balance might be more clear in this slide.

Note that the Ellery has a sprung over hairspring, an applied index, key guard, and Fogg's safety pinion; not on the Home.

Note the Home has "Boston, Mass" engraved on barrel bridge versus "Waltham, Mass" for the Ellery.

This example Home has top plate jewels (11J); most Homes are 7J, but don't assume all are.