Easy fix is get an old shaggy bedspread cover like granny has on her bed, you know the pink one with a line of shag then plain, rip a strip, wrap it around a flat stick until its a tight fit inside the case then use a stiff mix with extra catalyst of Vinyl ester and microfibres. As you go up and down the case it forces resin into the holes and smooths all the other imperfections. Works a treat and can sail in an hour