Apologies in advance for the crap cellphone pics. I had a small window of access to a really nice Southbend lathe today, and took full advantage of it. It was a little challenging to make a square piece of solid PTFE Teflon into a perfect circle, but I was able to do it. The material was also a little harder to work with than I thought, as it likes to pull into the tool steel if the chuck speed is too low, and stutter when run too fast.
All things considered, im pretty happy with the way that my new chain tensioner wheels turned out. Now I just need to find some way of pressing a bearing into the center of each piece!