My research indicates it's a copy of the Bradbury A1 Repairing Machine from the early 1870s (1871-1872)!
http://www.sewmuse.co.uk/bradbury/a1 repairing.htm
I believe that the shuttle arm needs adjustment. When I received the machine, the installed needle was broken! I've run across THREE methods to install the carrier and shuttle, and ALL seem to be off by 10°-15°of rotation, and the thread doesn't get picked up! It just gets tangled up under the plate!