CD,
So, it would be safe to say that my 1919 vintage 66-? treadle machine, which now has a low shank presser foot shaft, left the factory as a back clamp machine and was later converted.
Currently I have three red eyes: a 1913 vintage 66-1 that still has it's back clamp presser foot shaft, and the motor boss, a 1919 66-? that's probably been converted to low shank and a 1924 66-? that also has a low shank presser foot bar.
How can I, or can I tell for sure which type of presser foot shaft the machine came with?
Joe