I believe the serial number is behind the pillar below the motor. I'm guessing that it will start with 41X or 43 making the model number the first digits.
This machine does
not use a belt and is driven by a rubber wheel on the end of the motor. There is usually a flat spot from resting on the hand wheel. Some have filed them down or sew-classic.com has the part.
The hand wheel is rotated opposite what most of us are used to, going in a clockwise direction when viewed from the end.
You can find more information on this thread
I couldn't resist. I had to bring her home. and how to load the bobbin can be found at
http://www.quiltingboard.com/vintage...c-t172420.html
My
41x xxxxx was dated to 1940 and my
43-xxxxxx had a 1955 dated guarantee.
Janey - Neat people never make the exciting discoveries I do.