I recently came into possession of a very nice set of Shimano DA calipers. Now I very familiar with DA from about 1980 on (7400) but these are unique. From searching the web I believe (from a Sheldon Brown detail showing the 1973 DA catalog) these are from 1973, the first year of DA. They are simple but elegant and in very good shape. I was wondering if anyone out there knows if these are gems/junk or somewhere inbetween. thanks, in advance, for any help on these.