Seems some bright spark thought....."hey wern't those old motorbikes just push-bikes with motors?"......and had made his own custom. Looks just like an old 1900's Harley or Triumph.....but in reality is using a newish honda 50cc on a newish huffy frame.
Has got me a thinking. I wouldn't mind doing something similar. Hopefully you will see something in farrst developments along these lines soon.