The excellent CuriousMarc YouTube channel just started a new video series refurbishing a B-52 astrotracker, going over all of this in some detail:

https://www.youtube.com/watch?v=GkEjLqu-JH0&list=PL-_93BVApb...

Recommended.

It also immediately occured to me how much easier this should be on a copter, since you don't need a gimbal'd platform :)