Index plate for dividing head

This is an index plate for a dividing head http://en.wikipedia.org/wiki/Indexing_head, used with subtractive processes on milling machines or lathes. I wanted to see if I could make a plate with different combinations of holes than were available, but still need to check the dimensions of the center hole and total diameter for compatibility.

The rings of holes are primes (13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 52). You can use a geared mechanism to divide a circle into any number of parts.