I have never seen one of these but my buddy offered to trade it for my home built tandom frame I got back last fall since I don't have one I had to have it. Its lugged except the cantilever bars with a 3 piece crank.
I had an Austrian built red JC Higgins cantilever bike . It was a 3 speed also. Sturmy Archer if I remember right. I sold it to Dan at Ichi Bike. There are pics on his website under bikes for sale.