Hi Ray..did you ever get an answer on this?
My knobs were so badly faded, cracked, broken and/or discolored I bought new ones. Unfortunately somewhere along the way someone had put an incorrect carburettor in the car and there was an incorrect cable. Chris, host here, had a cable for me but the knob end was knurled (for a push on knob) while the new knob called for a threaded cable. I ran a die over it and was able to screw the new knob on the cable.
Not sure if it helps but just trying...