Thanks, George!
Renners, I started at 60 and worked up to 1200. I could’ve gone finer on the resin, but I ran out of patience. Note that I don’t just sand on the lathe. Following a tip from Kenny on sanding pens, I first sand with the lathe running with a given grit, then stop the lathe and sand end to end until I have the scratches running both ways. Then I step up to the next grit. Lather, rinse, repeat. It takes longer, but I no longer get in the situation where I had a scratch running around the piece from the 60 grit that I kept hiding through the higher grits, but never really completely removed. By sanding the other way, I find and fix any problems like that almost immediately.
Well, except at the end of the piece. You can see, in the first picture, a small scratch running around in the green about 1/8 inch above the walnut base. Somehow I missed that one. Dammit.