[68panelman]

You have Yankee 77's. They have a single screw towards the rear of the lens, if they were glass, over tightening the screw would surely break the glass. The glass type used a metal base with gasket, then glass lens with gasket, then a chrome bezel to hold it on. California sun got the best of those. There are repro 77's in a all plastic housing you can get for $30 I think, I have a set here that came with a truck I got. I do remember replacing original lenses in the 1990's for the same white-out condition as yours for $12 per lens on a 70 K-10 lwb step side I had.