Looking good!
I've done a fair few rings, and they can be finicky. My tips:
- Absolutely take your time when sizing the hole for the insert and when actually turning. The better the fit between blank and insert, the fewer problems you will have with turning. And when you're getting close to final dimension when turning, you're working with such little material that the slightest catch can blow the whole ring up.
- Cover the interior and sides of the insert with tape when gluing into the blank. This will save a lot of cleanup later.
- With a film finish, unless you're dipping the whole ring, go with many super-light coats of finish to avoid getting finish on any of the metal. Rings get heavy wear, and many finishes can delaminate from metal if everything wasn't perfect when the finish was applied. Wearers also have a tendency to pick at finish that comes off the metal, and they can accidentally remove finish from the blank (or cause tear-out) while trying to get finish off the metal.