i took the thing apart, ironed the old cover flat and traced it out on some denim from old jeans. you could use any fabric, i didnt have a staple gun to re-attach so i laced it underneath befor i put the plastic cover back on the bottom. i think there is a metal one on ebay i'd go for that.
free fix, plus i have a butt pocket on the lid that keeps emergency cash, insurance, reg, etc...