Thanks to all for your suggestions. Joe Williams is the lucky winner with his advice below:
One thing you might want to try is just twisting the light switch left and right. The dash dimming part of switch is little more than a circular coil that makes contact with a piece if metal mounted to the switch knob. It can get rusty and working it back and forth will often times wear away enough oxidation to allow the dash lights to start working again. I'm talking about 40-50 turns..
We fiddled with the switch very slowly and the lights intermittently came on. We turned it back and forth as Joe suggested, and we now have lights!
Once again, thanks for everyone's help!
John