I took an old rusty free spirit frame and welded a crossbar. I took the old rust seat base plate and welded/brazed on a new back and included a locking trunk. The foam for the seat I cut half as thick and then sewed a $4 thrift store leather jacket around. I brazed the tank out of old bumpers a local autobody shop was throwing away. The engine is case induction was made possible thanks to the assistance of snordly.