Back in 1959 a cousin gave us two old not running, Whizzer engines. They were made to convert a regular bicycle into a moped. I suspect these were made in the 30s.
My older brothers were able to get one running from the parts. The only problem was we had to push it to get it started as they could not get the starter to work. You would push it, then engage the engine then when it started, you had to jump on it before it ran away.
It was actually a neat machine. It would easily pull my best friend riding on the handle bars and me up a steep hill.
Those are worth some bucks today.