But wait, there's more! (He shouts, madly waving his Ginsu steak
knife.)  Ever had the problem of having to align to the edge of a piece
of stock angled in the milling machine vise?  Drop the body of the punch
over the edge and use the edge finder to locate on its circumference. 
Since the diameter of the punch is known (or can be easily measured),
it's a simple matter to locate the spindle axis directly over the edge.