Need help on pads for Porter Cable 7424

[Late Apex]

I have a Porter Cable 7424 that has sat for awhile and the black rubber/foam pad has deteriorated and fallen off the flat metal disc in pieces. it appears it was just glued on? Which pads and where is the best place to get replacements? Im also not sure how the pad was attached as it sort of just fell apart off the round metal plate. Does the pad have adhesive for the metal disc or what? I need an item number or reference to get the right replacements. The old pad had a slant to it around the sides and not squared off. Thanks in advance.