I started commuting to work again today. I think the transmission is making slightly more noise than before but otherwise the car is fine. The RPMs are limited to 5300 RPM, so I won't have any resonant activity. I'm really happy that the tachometer is hooked up. It really helps me keep tabs on what happens to the motor/transmission at different speeds under different driving loads. It's also much easier to watch than the speedometer hidden behind the right edge of the steering wheel.
The car also seems to be unaffected (so far) by driving in the rain. We'll see how long that lasts. I do have issues if I get in the car all wet from running through the rain, since my body heat evaporates the water and fogs up the windshield. Turning up the vent fan on full helps quite a bit, but having the hair dryers will definitely help.
I called Rennsport Systems to ask for a transmission rebuilt quote and they suggested budgeting between $2000 and $3000 for parts and labor (Ouch!). Alan at A &P quoted about $425 for labor plus parts (better). I could also get a transmission off e-bay for about $375 plus shipping. With the spare parts I can salvage from the second transmission, I'm thinking that having Alan do a rebuild would be the best thing.
My plan is to drive the car for a week, show it off at the EV meeting on Thursday and take it in to Alan on Friday (if he has time) to upgrade the brake cylinder and align the front end. We can chat about the best direction for the transmission from there.
Perhaps I'll work on the fuel gauge in the meantime.