Brake fitting question,(pics)

[MonzaRacer]

No the helicoil is fine for a bleeder line fitting but not a brake line hole, then you need to have it eithre welded and repaired or drilled and tapped to next size fitting and attach appropriately.
As for putting it under the ubolt that is theway I would do it. Find a piec of pipe to form the lshape over and use a hammer and form themetal to the curve of the axle tube then simply slip it under and retighten the ubolt.
while heating up in the area of the nuts to help remove the nuts heating/welding (unless you removed uit and had a specialty welding shop heliarc and retmeper it) I wouldnt weld on the curve as it alreadhas the stress of the bend in it.
also if the reaend isnt installed ,pull the axles out, drill and tap the hole seal and install it with a bolt or stud and then tack the bolt head or nut to the bracket, if you gotta remove it grind the tack off.
little more work but you could also use a race bolt thats drilled for safety wire and get a safety wire pliers to wind your wire making it look trick.
Good luck in what ever you do.
Lee Abel