Don Foreman wrote:

You might grind a shim out of HSS (piece of lathe bit) and
silver-braze it in place -- or silverbraze it in place and then grind
to dimension and shape.

HSS doesn't seem to lose any hardness from the heat of silverbrazing.
That isn't based on any measurement, but cutting tools I've made
that way seem to keep an edge as well as unbrazed ones do.

I thought about that, Don. It seems easy enough to mill out a little bit
of O1, leaving maybe .015" tolerance, harden it, temper it, and grind it
dead flat on the surface grinder, though. If I decide to permanently
attach the shim to the fixed jaw I'll try brazing it although every time
I try brazing it seems to fail miserably.

Grant