So I searched the Net for a few weeks and decided that Mel Bartel's idea was perfect for the job. Mel's elegant design is absolutely brilliant and easily within the reach of the home electronics hobbyist. I copied his circuit and designed my own prototype circuit board using a shareware PCB design program. Mel's software is superb and is in fact being improved as I speak. I modified my version of the layout slightly so that I could have either handpad control at the eyepiece or from the remote computer control.
Software controls the 'microstepping' of the motor which results in a smooth, error free drive.
The only errors involved are those in mount flexure and gearbox backlash, which are either negligible, or can both be minimised by Mel's software. A close up of the Declination Encoder is shown below, salvaged from a mouse. This recent addition to the scope has changed the pointing accuracy of the system about four-fold. It previously used the two aluminium disks. While this was fine for backyard observing, it had it's limitations.