This is designed specifically for the Astronomers without Borders OneSky telescope. The ring gear is split into 3 pieces that fit very snugly, might require a touch of sanding. The snug fit and shaping around the upright means only one screw is needed to mount it. The worm gear adjuster screws to one of the lobes that stick out the side (2 small screws) and the gear can slide out to allow for large movements.
Update: Added degree markings around the ring gear per request
The author marked this model as their own original creation.