JB Weld/Epoxy...scuff it up with some coarse grit sand paper first. You can set a fender washer, and then the jb weld/epoxy to add durability. If it doesn't hold up, you are out the money for the epoxy and the washer...not gonna break the bank.
I have a jb weld trail fix on my husaberg ignition cover that has lasted several years.