After discussing with Kevin about the finer points of silver brazing, here is the joint criteria and brazing procedure.
The spindle is 1.249 Dia.
The bore is 1.255 Dia. x 1.60 deep
This leaves an annular space of .003
That calc's out to .0189 cu in which equates to about 6" of 1/16 56% silver solder.
Preformed a 7"coil of solder to rest on the shoulder of the end bore.
Slathered the bore and spindle with white brazing flux prior to assembly.
Having not silver brazed anything with this much mass, I was a little concerned about getting enough heat on the spindle inside the knob end, without burning the flux.
Used 2 weed burners for both the initial preheat and to bring the knob end up to temp.
The spindle was heated with a #6 welding tip.
The joint was heated to temp, until a ring of solder could be seen at the bottom of the joint.
Then rotated the joint 1/2 turn, while continuing to heat, adding another couple inches of solder at the top of the joint.
It went well and I feel that this a good stout joint