Got my motor today. I found the seller on Craigslist, but since he lives on the opposite side of town (about an hour away). Luckily, my coworker lives near him so had him pick it up for me and then bring it to work the next day.
I tried to reuse the pulley (sheave) and key from the old motor but I think Ridgid used some kind of non-nema standard motor which doesn't fit. I had to order key stock and a new pulley from Grainger. I'll update my cost list in part 1.
Balancing the Wheels