Instrument Panel (odo/tach/speed) Question

I have a 91 RS Camaro w/ a 305. Recently the odometer, tachometer and speedometer stopped working. All the other guages like temp and fuel still work. None of the guages are digital.

I took the instrument panel out just to check that the circut board board connections where all clean and they were.

My questions are:

1. Does anyone know where the speed sensor is located? Is this easy to replace and is this most likely the problem?
2. Am I correct to assume that a speedometer gear w/ a cable does not exist because the instrument panel is a circut board?
3. Does this sound like the instrument panel itself is broken?
4. Any other ideas?

Appreciate any help, and thanks in advance.