I carefully looked over the entire mechanism to decide which parts to keep.
The main circuit board worked and using serial could be commanded to go to a position or even store positions, but it lost out due to not supporting the speeds I wanted to control. I specifically wanted to be able to go from 1 revolution per day (About 0.0007 RPM), up to about 15 RPM.
Even if the board couldn’t be used whole, it still contained bipolar stepper motor drivers. It used matched pairs of L297’s and L298’s. I quickly decided against using these due to the simplicity and size of the EasyDriver.
The Pan and Tilt axis both have magnetic sensors for “home” positions. I’ll probably add limit switches to the Pan axis, mainly for when it powers up to calibrate itself. If I didn’t, the only way to calibrate the Pan axis with a “middle of travel” sensor is by traveling full travel in one direction (hitting the physical stop and stalling the motor) each time, which just seems plain wrong.