I think stock are 18mm with a 6mm backing plate
PP Brembo are ~15mm with a 5mm backing plate
Carbotech matched the numbers above for the stock. For the Brembo, Cobalt says 15.3, but the PFC pads I get measure about 14.8 with a 5mm backing plate.
Gray is roughly the AP pad shape. :

Area/volume numbers are my estimates and may not be correct - the rest is from drawings from Cobalt Frictions website.