II’m 6″ tall. With my chin on the tank, my arse ends up a couple of seconds behind! The seat will be quite long as a result and the rear-sets even further aft.
After playing around with pencil and paper getting proportions correct, I built a CAD 3D model, sliced it like a piece of virtual bread every 16mm, then printed and pasted these offsets onto 16mm customwood. Some jigsawing and glue created what looked like a wasps bum. When sanded smooth to the glue lines, the intended shape emerged.
My friends Peter and Steve of Applied Composite Technologies made a female mold from my ‘plug’ then they laid it up with carbon/epoxy to create the finished part. The pointy end was taken off and some curves introduced so that it looked the business on the salt racer.