As an example of an alternative setup for a cross slide DRO (X direction), I submit a picture of what Precision Mathews did on my PM103V. The DRO is on the far right, attached to the cross slide via three screws with spacers. It is a simpler installation. However, I lost about 2" of usefulness of
the tailstock spindle length and had to grind a hex key to use on the cross slide lock cap screw. Not complaining, just presenting an alternative installation. As a rank amateur, I have found the DRO to be a great help.