"You'd be better off fixing it under a microscope and filling in the
cracks, like making a scratch model ship."

That is what I figured. What is the best material to use to match in
the look and color of the old knob? I searched for black epoxies last
weekend at the usual places with no luck. I was going to fill in the
outer cracks and holes where no "chips" could be found and then
reinforce the inside well, as it broke where the speed tuning handle
mounted (poor packing).

Dan