Oh wow. That is exactly what I am doing. I included the threaded ends in the measurements. Thanks for that clarification.
I appreciate all of the information & encouragement. Right now, it seems like every bike shop near me is just jammed and really can't be pestered with questions. Out of curiosity, I asked about this job and they said they couldn't do it this month (!). However, I feel like this is something I would like to know how to do. I take all kinds of things apart - and put them back together with very few extra parts... This is really the first time I've done this and I imagine I'll need to get some new tools to handle this. Rookie mistake. Anything else I should be careful about?
I was thinking of putting in sealed bearing sets for this. Right now, the Miyata's BB feels like it has a lot of grit and is really not moving smoothly at all. Any suggestions? I figure that, once I have the tools and become familiar, I won't mind replacing the bearing set every few years.