Are you going to run cable guides for full length housing or stops for bare wire? Guides for full length don't really do very much and neatly trimmed tape stuck to the insides of the guides works. The stops for exposed cable see the full braking force and need to be bare metal digging into the paint. I'm guessing this was full length like my old Fuji Pro and the vast majority of the bikes raced in the mid-late '70s. We never used tape under, but then we had no idea we were riding bikes that were "vintage". To us, they were just bikes. We did all kinds of obscene things to them like racing and crashing.
Edit: beautiful paint job! I've used good electrical tape on steel clamps with OK results (as long as the clamp shifting isn't the end of the world). Do seek out good tape. Like duct tape the range of quality is big. I love the DT stop for the shifters. I ordered that for the custom of my username. The bike never did see Campy shifters, went to the top-mounted SunTours when they came out in the early ;80s and now spends its time as a fix gear. (Horizontal dropouts like your; just so I could. Never thought I would.)
Ben
Last edited by 79pmooney; 03-28-20 at 05:59 PM.