Dial indicator holder that guarantees perfect stylus alignment

I use Indicol on Bridgeport patterned mills (upper right at 4 second mark), long as I can remember, always found it satisfactory. That is not including look-alikes, with inferior hardware - especially the wave washers.
But the clamp not suited to other diameter spindle noses, solution in the video I'd rank as first rate; for spindles that have a light enough spindle to turn by hand in neutral.

More important is a 38'' video with all the details required for DIY duplication.

Dial indicator holder that guarantees perfect stylus alignment - video