Right now I'm planning on going the lead route myself. It is "extra" so it might slip out of the plan for money reasons but like some of you, I think that is the "right" way to do it. Plenty of shops use other, more common fillers(fiber enforced filler, AllMetal, regular filler) and methods though without issue based on what I've found out. I think as long as whatever the choice if it is done well by a skilled individual, it will last.
They don't really use "lead" though due to health and environmental issues. It's some other similar "body solder" product. So some might argue "but it still isn't 'lead'"
I'll update with pics once the time comes.