Elgin Grade 73

Elgin's grade 73 is another 18 size movement, with 7 jewels.

This example, made about 1897, has an unusual open-face case.  The front and back edges are broader than typical, making the seam on the front and back more exposed to the front and back respectively.  It makes the case a little harder to open since there is less turning surface on the side.  But it changes the look just slightly.