The saddles seem to be consistent, in a bad way. In a production machining environment, a pass would be made across the saddles from one end of the head to the other, and then a stepover and a return pass back to the starting point. Why they don't use a 7/8" ball mill and make one single pass defies logic.
A radius gauge may fit reasonably well after the heads have been run awhile, because the high spot will have flattened out. But, any light under the gauge means the radius is not true, and the contact area between the shaft and the saddle is reduced.