replying to irox, irox wrote: Answering my own question. I seems that the Smith Drum Extension Gap lathe was nearly identical to the Fay & Scott extension gap lathe. I would guess that Fay & Scott made them first, when they couldn't meet demand during WWII the government contracted another company to make more from the same design. Of course, it could have been Smith Drum's design give/sold to a bigger company which could meet demand. They even have similar (the same?) model numbers.
Anyway, here is the "War department Maintenance Manual and Parts Catalog, Lath, Engine Extension Gap Electric Motor powered Model HK 14" - 28" Fay and Scott" from 1943:
Hope that helps some folks with their Smith Drum Lathes!