Mounting Z axis DRO

Hi

Has anyone mounted a DRO

http://www.hobbymetrix.com/images/vert_scale2.jpg

on the Z axis of this type of mill.

http://www.grizzly.com/products/G3616/images

I'm pretty sure I'm going to have to move the power switch box outwards but
since there's no access to the spindle in the middle mounting and moving the
bits seems a bit perplexing.

I'm thinking a mounting bracket to the side of the head for the bar and then
a clamp onto the Quill with a long upwards pointing arm that attaches to the
body of the DRO.

Or would it be better to mount the bottom of the bar to the Quill and fasten
the body to the head. Then the bar moves up and down while the head stays
at the same place.

John Dammeyer