Originally Posted by
Kactus
If you want to go original. the correct brakes for a '70 Professional are Campy Nuovo Record sidepulls according to Sheldon Brown.
http://sheldonbrown.com/retroraleighs/professional.html The '69 Professionals used Weinmann centerpull brakes w/quick release brake levers according to the same source.
With Mafacs or Shimano 600's I do not think being original is the concern. Silver lined housing for brakes is what I would use, the trick will be possibly getting ferrules to fit the housing
and the various parts w/o any binding. Some housing is of a bigger outside diameter than others. You might look at what Velo Orange has on offer.