Red spots in clear plastic sprayhood

[Manta99]

I brought my sprayhood to a loft in Fiji to have some stitches repaired. When I got it back, I noticed a lot of brown spots on the clear panels which weren’t there before. The loft claims they were there already and say it’s deterioration from the sun.

Anyone has some experience?

[Island Time O25]

Was there any grinding or metal cutting done around this? Could be the rust spots.