Bah--I are bike mechanic with access to toolz. But thanks for the alt advice. Park BB facing tool also chases/threads at the same time, so it is the way I'll go as part of the bb shaving process. If the bb doesn't hold on whatever's left of the threads, I'll go with a VO threadless bb. At 68mm, bb will be correct width for that application.

Front end will be threadless headset mod, like others have done, with BMX seatpost stem.