His other hobby is collecting studibakers, so an interesting guy.
I have a feeling this train is about 25+ yo .This-and others he’s made- have motors. They set up the tracks and give rides for kids (and big kids!) on occasion.
I remember when i was young this same uncle made a mini army jeep for his kids,powered by a mower engine.Sadly i never got to drive that one!

Also, he was into remote control planes and was one of the first to try building a model helicopter.I saw it in the late 70's.It wasnt real small-the rotor spaned about 1 meter.
He never did get it to fly properly because the engines at the time just weren’t strong enough