Great thread!
I don't know if this is too technical for the interwebs, but what sort of flame you're using for fillet brazing? I've had relative success with a soft flame and the sequence melt brass puddle, back away and let solidify, add on top, repeat going around... But my fillets are kinda small. Too strong a flame and the fillets melt away on the side, but even with the soft flame I can't stay long enough to build a large fillet...