I thought Betsy Ross machines were toy machines, but I did find
https://www.collectorsweekly.com/sto...arles-williams There is a thread here on QB
National Improved Eldredge type B manual? that I think maybe helpful as it would take a needle that is not readily available. There are some work-around methods to use a modern needle.
It is recommended the you wipe it down with cotton balls or cotton fabric and sewing machine oil - NOT 3-in-1 oil. This is to preserve what decals are there.
Not that a serial number will be particularly helpful, they sometimes are on the front slide plate or on the bed of the machine after the front slide plate is removed.