[litlmikeyl]

I snooped around a bit more on the interwebs and found the attached picture on another site. The ST-745 is on the bottom with two other bare spindles pictured. Also found was a service kit sheet for the spindles in the attached picture.

Given the thread size for the top nut probably wouldn't be a goofy size due to it's age (read: its too old for a strange SAE or Metric thread) and seeing that the OD of the shaft itself LOOKS darn close to the major diameter of the threads, a slight modification just might do the trick to the use of other bearings.

I'm curious what you come up with Greg. This discussion is veering me towards what your doing instead of buying the new big bearings or swapping out the housings.