I had to replace all the cable guide on my Ciocc project. You don't even need an oxy/act torch setup to do simple braze ons like that. That's a diver's helmet style braze on you can get from Nova for less then $2. Just use a Mapp/Air torch and some silver as you won't make a brass brazing rod even flinch at melting with Mapp.
http://www.cycle-frames.com/bicycle-...-S-HELMET.html

...or you could just unbraze them and just use cable guide clamps instead.