Last year my Smiths speedometer stopped working. I found 2 small brass discs on the floor of my SPF. One was concave and the other was flat. They go into the speedometer and keep the gears in line. I want to put the washers back in and epoxy them in place but need to know which goes in against the gearing.
I can't answer your question, but you will get more responses in the SPF or one of the other tech Forums. I never used Smith's gages so I have no knowledge of how they are put together.