Minimising "striations"

I have been going through some old JPGs from 2006 taken on a Pentax Optio 550. Many shots have bleached-out highlights and the camera developed a fault that produced what I call striations. Once I discovered the fault, I ditched the camera.

I am playing around to see if I can reduce this effect and would like suggestions on whether I am pursuing the best plan to try to make a silk purse out of the proverbial sow's ear.

First off, I am using the Colour Enhancer to reduce the cast in the red, purple and magenta channels. This leaves grey lines. I have tried cloning them out, but it's very laborious. In this sample therefore, I created a duplicate layer, and used the Tone Enhancer with a mask to boost the highlights in those areas and remove the lines. I then created a stamped layer and edited that further. This is an especially bad example as the highlights are completely blown. But I do have some slightly better shots which would still benefit from salvaging. I am not cognisant with the Blending Options, so have no idea if one of those would help. Thoughts anyone? Thanks.

Original:

Edited, on photo with layers: