"For the back of the camper." A kind of folding bike +. The Honda Monkey's, they are called that because the rider M / V was sitting in a 'monkey position', are ideal machines to tie behind a camper.
These machines were offered for the first time in '67-' 68 and are pretty much the most minimal motorized traffic in all respects. Only the front fork sprung a little.
Later models of the Honda Monkey were - as far as it is possible in that size - a bit lumpier design and got rear suspension.
In recent years, quite a few technically inferior clones of the Honda Monkey have come from China. So go for an original Japanese monkey for your monkey hunt.
These lilliputters are still regularly offered. Also from 'forgotten corners' because they are so small. For example, this copy of the Honda Monkey was left behind after a move and was only found a year later by the new homeowners.
So maybe it's a tip to go and look in your own shed this weekend.
And if there is a need for cleaning and refurbishing: the parts supply is still in good order.