I used David's fibreglass kit to strengthen it up where was needed and fibreglass filler to fill any big chips or dents (it can be messy lol ) then isopon fantastic bumper filler sand all down in between coats and I came across a stopper today to fill all pin holes and wee dimples in primer , great stuff rub it in with your finger and sand down down its gone 😊 Anything can be rescued 👍🏻