Headlight lens replacement
As these headlights age and the lenses becomes useless or cracked, I think that the entire front lens could be replaced.
The repair would consist of cutting a 1/4" of the front face tracing the vertical curve of the lens.
This would be replaced with a 1/4" thick piece of Lexan formed in an oven to the shape of the lens curve.
The OEM lens is curved from side to side but this would be ignored and only the vertical curve reproduced. The reason for ignoring the side to side curve would be because a simple two dimensional bend would be easier than the compound curve which would be much harder, requiring thinning of the center wall thickness which would produce wrinkles and therefore glare from the lens.
The compound shape could possibly be done by hot stretch forming but this requires more complicated equipment.
The new part could be attached by silicon and as the lens is partially hidden under the hood a neat finish with nicely rounded and polished edges it would hardly be noticeable.
How hard can it be?