Yeah, 82mm diameter sounded a little huge, but being blind the measurement process is, well, involved, and I just hadn't done it yet.

"A mm short" can be resolved with a spacer, but what about a mm long, as this is the situation I think I'm running into. If I read correctly (and chances are I didn't), the English thread is 29 TPI (aprox 1.14 threads/mm), so I'm guessing about half a thread too long per side isn't a concern???