I have an '81. I am trying to replace the original radio that the PO removed. It looks like the faceplate screws are small Allen head, yet I have tried every allen that I have. I get what appears to be the correct size and it wants to strip. I tried it in the other gauge screws and the same thing happens. Are the screws not allen head? Are they just decoration and I have to pull off the entire gauge cover to get to them?

 

Not sure how the radio was attached in the 81 but previous years had nuts around the tuning and volume shaft and the radio was removed from the back. There was a brace that supported the back end of the radio also. I couldn't tell from your post if you are trying to remove the original radio or an aftermarket radio but I suspect the Allen head screws you are trying to remove are merely molded in decorative plastic ones.