Originally Posted by VintageSteelEU

Quite interesting solutions. I like the second one more. Though soldering is definitely not my forte Something to look into sometime.

What I use is this:




As mentioned, so far I'm just checking the locknut on that headset to make sure nothing comes apart during a ride. Which isn't a huge issue and so far I didn't notice the locknut coming loose. This might be something to look into if I were to sell the bicycle.
There was another solution I was looking into, which was Nitto stem mounted cable guide. They do look reasonable. The prices aren't what I would call reasonable (some £30 in the UK) and they are not always easy to find. But they do look like an elegant design. I was thinking about getting one, but then I wanted the bicycle to use solutions or components which would be available back in mid 80's. The whole bicycle uses components from before 1987 (hubs are 87' I think, though older design Atom, rims are MA2, so introduced in 86') and the idea is to keep it this way as much as possible.