Well let me know if you are able to find anything to patch the plastic. I have not been able to find any repair material to fix the GM interior plastic, might try some of the flexible bumper material to patch chips in the kick panels but I think you would be better off getting some nice used ones from the local junk yard. Get a good set for not too much money, although a used dash may cost some bucks if it has no cracks. Any G body (Elky, Malibu, Monte, Regal, Cutlass, Grand Prix) will work for the kick panels and front parts, but the piece above the window that goes back to the rear panel is El Camino specific and may be more expensive. You can get plastic/vinyl/fabric dye at most auto parts stores in most standard colors, or have some mixed up to match original specs at a paint shop. Be sure to get a can of plastic prep as well, this clear spray goes on before the first coat of dye and you spray it on, wipe it off and the color coat sticks better. For damaged dash easiest and cheapest fix is a one piece dash cover as sold by The El Camino Store and others.