The gasket that you made is also a spacer between the drive mechanism and the tach cable. If the cable bottoms out it will push that tiny spindle eye and bind it up. You can test it with ur drill by applying pressure as it spins. If it binds, then you need to relieve that pressure. Also, use greaseless lube like LPS 1. No grease.
Also, that gasket also has a spacer similar to the screw spacers but on the inside of the housing. I would glue them to the inside gasket. Those spindles are very sensitive. They used to be available on EBay. Good luck and good to see u and ur father back at it.
