Well, Folks, I did it. After viewing the excellent video by A&G Engineering about four times, I bucked-up and went for it. I guess the method amounts to "line boring," but not sure that is the correct term. Basiscally, with the crankcase bolted together, run a dial indicator around the inside of the outer race to about 0.0002" within center of the mill quill. Remove the drive-side half, then bore the bush. That almost makes it sound easy, but being a novice machinist, the setup took me about 4-1/2 hrs.
Before I even clamped the timing side to the mill table I measured the slop in the quills of the two mills available to me. Days before, I turned a test plug 0.0002" under the journal diameter so I would know that the next adjustment of the boring head should be the last. After the timing side was clamped to the table, I verified square with the quill in both the X and Y axes. From what I could tell, A&G only checked the X axis (not to say I could do this better or, even, as well as the gentleman).
When all was done, I finished at 0.0013" +/- 0.0001" over the journal diameter. The finish in the photos looks rougher than it feels and I doubt a mirror finush is required. Clever observers may see a little glitch (like a shoulder) at the end of the bush that is about 0.002" deep (on the diameter) and 0.020" long. True confession is that I miscalculated the last adjustment but caught myself before running further in and destroying the bush (and all the setup time).
The bush fits very well over the journal but, fact is, I'm yet to put the cases together since the machining, so, I'm yet to prvove smooth movement when assembled. Last time I was at the machine shop I tried to turn a dummy bearing for testing shim fit, but that went horribly wrong due to my material being too hard for the cutting tools (four hours I'll never see again).
I have more pictures I might share, but out of time right now. Thanks for reading and advising what I've done wrong (or, even, right). The only damage right now would be to a replaceable bushing.
Richard L.