Lots of astrological symbols plastered on the standing figure on the left. Also, on the banner above the guy on the right are symbols for some of the planets.

I'm guessing that the rings of letters and numbers are tied to a book that accompanied the instrument.

Probably had a now missing pointer that was tied to the arm on the other side via the central hole.

More shamanistic BS that passed for real understanding back in the era when barbers did surgery on the side.