When the PCB is potted into the metal core it must be machined down to its final dimension and then polished. Interestingly several of the components are partially located outside the final dimensions of the ring. This means that the machining step will remove parts of these devices. For example the LEDs making up the display are intended to intersect with the final polished surface of the ring. This is done to make the ring as thin as possible.
A big challenge for polishing is the fact that the final surface of the ring is resin. Currently this is an epoxy resin, though I will try polyurethane also. These can be as hard as 90-100 Shore D. This is enough to be polished to a high gloss. Though rings are notorious for getting scratched, even when using relatively hard metals. Being worn on the hand, they are constantly in contact with other hard surfaces, grit and other jewellery. This is still an open question, and will be a big factor in whether the product is viable for sale.