As [USER=1328]@warp9.9[/USER] said.
The factory made a few R3 accessory upgrade seat options but you can get your Corbin re-upholstered by any decent upholstery shop for a reaSONABLE PRICE, IT IS JUST A LUMP OF FOAM. Not yelling phat phums.
The Corbin characteristics and design of the seat is retained.