The top left photograph shows a range of jigs. These were used when drilling the stepper motor ends caps and also the mounting holes for the encoder boxes. Once assembled, follow through punches were used to mark the hole positions, from the encoder housings.

 

Photo on right. The original X and Y screw blocks, were copied in aluminium. Having used the lathe to true up some block in a four jaw chuck. The original dimensions were copied using the, (top hat) punch guide in the screw. 

 

Note the special pointed screws, made as follow punches, to get accurate measurements of the mounting screw spacing.