From the sounds of your machine you have an "embossed White" like the one pictured
embossed White machines From my research it is dated around 1930. The vintage forum on Quilting Board is at
https://www.quiltingboard.com/vintag...thusiasts-f22/
Maybe Leon can help you in the morning regarding the wiring. It appears your wiring may be different from any of my White machines.
Since you said it sews great, I'm guessing that you have already figured out the hand wheel goes the opposite direction from Singers. Did you get a manual with it?
Also it sounds that the direct drive rubber doesn't have a flat spot like many of these machines tend to get. It is recommended that one puts something between the motor and the machine so that the rubber does not rest on the hand wheel when the machine is not in use.
Janey - Neat people never make the exciting discoveries I do.