The 'S-U'  (Series Unique) designation was given to unique versions and with S-U hubs they have larger bearing size 1/4'' compared to the standard record size of 7/32'' they roll faster and last longer. 

This hub is completely original never disassembled, regreased or polished. 

It may be unique and if you have a very special build this would be amazing, I do not have a matching front but I do have a couple of used 28hole S-U fronts that with a little work would match up.