Bill I'm tending toward the same conclusion. Anything mechanical should either result in reduced speed or not starting at all. Maybe it's possible to bypass the board and just run it at full speed. And you may be right about it. Used Sears routers weren't worth much before. With Sears shutting down they are worth even less now. By the way, if the first 3 numbers of the Sears model number start with 315 then that router was made by Ryobi. There is a slim chance that might help.
Someone I consider a master woodworker once told me that a master woodworker is not someone who never makes mistakes. He is someone who is able to cover them up so that no one can tell.