One deviation I am making is to put rivets in the top of the seat flange to the underlying angle. My brother Ed did and says he sees RVs with this flange pulled up and away from the angle which looks bad. So I drilled #40 holes with dimple and countersinks so I can make them flush rivets.
Friend Jim Nelson had some questions about the seat and the three hinges so here is a photo of the drawing showing how the vertical seat can be put in any of the three hinges on the seat to adjust length from pedals.
