corvette outside rear view mirrowl

You may have to just buy a new after market look alike mirror. My 69 Corvette does not have adjustments or tightening screws. About $45 to $65 depending on the quality and seller. Make sure you tell them left or right side. The cars in these years only came with the driver side mirror. I also found if you swivel the mirror upside down, so it is lower, it will slightly tighten and not get buffeted by the wind at highway speeds.