Very cool!!!
I know the shop I sometimes do weekend stuff at gets repair jobs for British formula cars all the time. They are always brazed tubes. The owner chops up the replacement tubes, gets them all fitted, gives a little tick of a tack from the mig, and once the tubes are all in place, brazes them in with the standard torch. More serious and or difficult brackets and things he Tigs.
Gonna mention the Mig Brazing to him.....