I had one in the days before MIG welders were popular. It was an
attachment to a regular arc welder transformer, and I thought it was OK
and quite easy to operate. I did most of my car bodywork repairs with
it as it was pretty impossible to weld thin metal in the conventional
manner without blowing holes in it. MIG is now much better and
stronger.

I don't think brazing is acceptable for car body repairs nowadays,
least not on structural items.

I got the electrodes and brass rod from a welding supply shop. You used
to be able to find these in Halfords.