You are correct Scott, the spindle size for this crankset is 3U. I still have the original BB that was matched to the crankset on my 1982 Nishiki Cresta when I purchased the bike new and the spindle is stamped 3U, and E210, one of the cups is stamped Kawamura Japan.

The dimensions of the spindle are D Length Overall: 127.0, A Length Left End: 35.0, B Length Middle: 52.0, C Length Right End: 40.0. Note these dimensions are slightly different than those on Sheldon Browns chart. Unfortunately the races on the spindle and cups are slightly damaged as well as the bearings but I'll include the original BB in the deal if someone wants it.