Originally Posted by cyccommute
The cable stops that timcupery suggested should bolt righ on to the studs on the downtube shifters. Remove the old shifters and the cablestops bolt right up. That's how I converted my old Miyata to STI. Most bike shops should carry the Shimano cable stops.
His frame doesn't have braze-on downtube shifter bosses and the bosses on clamp-on downtube shifters aren't a standard size or configuration. The usual Shimano or Campy cable stops won't work.