• nice frame and although this doesn't directly answer your question as to who is the builder the Campagnolo Portacatena driveside dropout most likely dates it from '78 to '82 as this was the short lived period they were fitted on a lot of quality frames, the reason for the two holes....<< http://campagnolo.wikispaces.com/Portacatena >> also the frame/fork number should narrow the search. good luck!