Thanks, and for the plastics I bought all Honda CRF plastics, tank, and seat from ebay. Chinese copy known as "pitbikes" The tank and the seat and plastics all screw into each other, easy bolt together. For the tank I drilled two holes in the upper tube and installed aircraft Riv-Nuts. This made the tank bolt onto the frame rail. The seat is a seat post, cut off short, with a steel plate welded to the top. The seat was drilled and riv-nutted as well so it bolts onto the seat post plate. Too install you bolt your fuel tank to the frame rail. Bolt all your plastic mounting tabs to your seat bolt holes. Slide the seat and all the plastics as a single unit into the seat tube, and then install the two bolts that attach the front plastics to the fuel tank. Everything is very securely fastened, and looks professional, actually a very easy task considering the way I designed the frame.
Can possibly adapt same technique to a conventional old school frame.