Other than the bearing size being different, which was already explained by another list member... the cups on pista headsets were smooth with no engraving on the outside. The Nuovo Record Pista headsets are sometimes confused with old Sport & Triomphe sets, which are all similar. Sport & Triomphe are smooth and chromed like the Nuovo Pista. Sport & Triomphe have the larger 3/16 bearings & only have 1 wrench flat on the adjustable cup. This is what i remember without actually checking catalogues.
Ben Cole
Shelbyville & Springfield IL
USA