Need help with Knobs
 

I have a 1980 SC, and Need to replace the two knobs above the radio (Fog lights, rear windos defogger). These knobs have a fibre optic type light filiment sticking out the back. I ordered 2 knobs from a dead car yard, but these had light bulbs in the knobs as opposed to this light filiment. Anyone know what years the fiber optic light filiment type knob was used?

Also, anyone know of a source for these?

Thanks!

Chuck

1980 911 SC