The push handle tube ( the bit with the throttle and cables ) has broken where it bolts onto the lower tube. Unfortunately the part of the tube with the bolt holes is missing I thought about brazing and drilling another piece of tube to the bottom of the push handle. It does not have to look pretty, just work. I have never done brazing before, is this possible/worth it ?

Post a pic.

Brazing/silver soldering is an art. It takes some practice.
If you don't have a lot of things in the way then a simple Turbo Torch that attaches to a MAPP gas cylinder, the right flux and silver solder and your set.