yeah i saw it and it did me little good, just looking for help for my situation
I took a sheet of 5051 aluminum, cut it to the same width as the stock seat, then bent it into the "step" required to fit the frame, added pivot hinges from the original seat, and the seat locking mechanism, too. Then, I added the rubber blocks from the original, back into the same places, omitting the ones directly under my butt, as the goal is to reduce shock loads to my damaged back. Along the straight sections of the seat, I riveted on some 1/2" x 1/2" aluminum angle from the hardware store, to improve stiffness. Then I installed (but later removed, for lack of use) the little Owner's Manual flap pocket.
Then I went to a boneyard and bought a Yamaha Venture seat (a giant seat) for $20, removed and used the pad. I cut it with a bread knife to get the shape that fits both me and my wife perfectly, then made a cover from naughahyde, a one-piece top with 6-piece sides, by hand. All seals were sealed with Pliobond glue.
That was in 1982. It still looks new today, and does not soak up water in the rain (an important note to think of when making a seat).
