Just looking for a method of joining the crank that I could do at home- all I have is a Miller 225 stick welder-
I'd never do something that intricate with it- although I have done some stuff I'd never have thought possible with it before.

I think you are probably right about the brazing temperature and over heating the crank- but then again, after chucking a crank up in the lathe and turning some metal off of it, I think that all the heat treat the crank has is probably a case hardening of the journal. It is quite possible that a brazed joint with full penetration of the
filler into the joint- all the way around would have more strength and less internal stresses than the small surface area of TIG welds I am seeing in the pictures.

If I build one, I will probably just get it TIG welded- to be on the safe side- but the brazing is kinda tempting to me.