OK, finally able to report back on this. Since turning seemed the best answer, as validated by Mr. G. ("Mr. Bill"? Oh, no!), I set about trying to figure out the best way to do it with limited skill and machinery. First problem was protecting the drive-end threads while chucked-up in my drill press (aka, poor man's lathe). After a bunch of head scratching and searching my garage, stumbled on my drawer full of electrolytic capacitors. Aha! Aluminum body of the cap would serve as a sacrificial sleeve. (When finished, there was a very minor impression on the peaks of the thread due to the chuck jaws, but of no concern to me.) Next, how to stabilize the points end without the benefit of a live center. Solution, small 1/4"-drive socket attached to a breaker bar in a vise clamped to the drill-press table. I was a bit surprised how stable this turned out (and turned).
With the "lathe" set up, it was a straightforward process of using ever-finer files as the cutting tools. Actually, worked my way up through four coursenesses before settling on the main meat remover. Turned out there was no real threat of breaking through to the dowel pins. I'd show the photo, but it's basically the same as the one I previously posted.
The first photo shows the sacrificial thread protector before trimming to length. Second photo shows the "dead" center in the vise. Third photo shows the rig ready to spin. Fourth photo shows the main cutting file and the dimple after the test attack. Fifth photo shows the result after a final run of 600-grit paper. Sixth photo shows a small amount of chamfering at the points end due to the dead center. No problem fitting the brass points plate. (In retrospect, was that chamfer there before I started?)
I have a video of the armature spinning, which I might post to YouTube. If interested, watch this space.
Apologies if I'm irrationally satisfied with myself for getting this sucessfully done.
Richard L.