I was just wondering at what point it would be considered not worthwhile condition wise on the plastic bumper surrounds for painting. I currently have the following condition on the front and rear bumper surrounds on my '87. I was going to touch up the surrounds at the same time as I paint my diving boards when I tuck them. Should I just find more suitable replacements to use as a base, or will a degree of sanding and prep work out fine for the ones that I currently have?

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Any help will be greatly appreciated. Thanks.