Interesting short cut with testing the part, but I would
be concerned about “repeatability”.
Tom would have to not only mount the part, back into the lathe chuck
in two directions, he would also have to position the lathe cutter blade
precisely in the original thread groove, and resume the lathe travel worm.
Somehow, I feel that there are too many variables,
with a greater chance of the final threads ending up, cut too thin and thus
loose fitting, if all isn’t repositioned precisely, after a part
test-fit. It may be OK for a smooth bar operation, but threading resumption
might be less forgiving, no matter how careful one is.
