I recently acquired an old Knight Kit R-100A receiver, and it is missing a
main tuning knob. I've scanned a couple of images in of it so you can see
looks. It is about 1.9 inches in diameter.
A photo of the front is available on the web at:
A photo of the back of the knob is on the web at:
If you have a spare, please send me a note!
Thanks & 73!