For the record I would advise against brazing the panels together....
Brazing doesnt fuse metal together the same way that welding does, basically with brazing your dripping molten metal onto red hot base metal and capillary action makes it stick, theres more to it but I am being brief. Basically if you grind down the braze the way you would a weld it won't hold together anymore.... the plus is it doesnt put as much heat into the base metal so there is much less a chance of warping...
If you have the equipment to braze then you have it to oxy-acetylene weld, I'd go with the weld
p.s. flux coated rod causes metal fume fever due to the zinc in the flux.... if you do braze do so only in a very well ventilated area while wearing a respirator...