As I was pondering world peace, entropy, and how to mount a DRO on
the Sieg X3 quill, I transcended to another plane...

The Super X3 has a flat milled on the front of the quill. The bottom
of the scale is attached to it. The scale is fixed in front of the head
and does not move.

My inchoate idea is to make a collar for the quill (2.67" dia), drill
and tap it for mounting the bottom of the scale. Take a length of
aluminum rectangular tubing and mill off one side of the aluminum tubing
of the correct size for the DRO slider, make a mounting base for the
slider for inside the tube.

Now the scale moves up and down inside the tube, protected from all
but the most horrendous impacts and swarf. The top end of the tube can
be closed off with Wisconsin chrome, er, duct tape. Use a parallel to
help align the tube. Use some bar clamps (?) to hold the parallel?

Now put superglue on the tube mounted scale, use the parallel to
properly align it, and press the tube to the face of the head.