A member here did a repair on the pad, I think it was Bruce Launceston, but I may be wrong .
A small sheet metal tab was made, it looked like a wide staple, adhesive was applied to the crack in the rubber, then the 'staple' was pushed into the rubber after the crack was pushed closed, don't know if the rubber was cut to help start the staple, after the staple was in, it was covered in adhesive .
Don't know if this will help you out or not .
I did a search, but didn't come up with the thread that had this repair .