sander the type that have stick on pads, to make new sandpaper pads for these... get some sandpaper/carburendum paper, draw the shape around the pad and cut out the shape, then get some good adhesive that has a tendancy to become tacky when drying, cover a thin layer on the back of the cut out and wait till it becomes tacky then get some cotton wool and rub over adhesive and let it dry out. ;-)
I know, you can buy the real stuff ,but innit dear. Dunno whether this has been submitted in the past?
-- Sir Benjamin Middlethwaite