Just pulled the capacitor and checked it on my multimeter. It's reading the correct capacitance. This part is so cheap though I think its still worth picking up a new one.
Might be worth your while to spray some contact cleaner inside those plunger switches, sometimes they can build up a bit of schmoo and pass limited current. Wiggle all the spade connectors to clean up the contact there, too. It looks like a fairly straightforward arrangement.
A final follow-up on the issue. @pontiac428 you were right about the electrical contacts in the plunger switch block. They were gunky and corroded and making poor contact. I fixed this and had full power back from the motor. However the two higher gear speeds were still not working. The motor was spinning but the spindle was not. Took the gear box apart again and found a fiber gear that had spun on its splines. I love simultaneous independent failures....
Sometimes, it's just that simple. Years as a mechanic taught me what to look for and how to be the right kind of lazy.