I'm afraid this isn't a viable suggestion, because the motor is pretty apparent and so there would be all kinds ol legal compliance requirements in USA

So, just sharing a fond memory

I spent a year in Toulouse, south west France, as a student 38 years ago, and had one of those VeloSolex things. What a daft and irresistible hoot. Tiny little petrol engine working friction drive onto the front tyre.

I took it all over the Pyrenees passes. It took a bit of pedal assistance, but despite the added weight it worked. I think it took about a half pint of petrol a month!