These guys used to make them for Riley:
http://ultimatedoorseals.com
You have to call them. They send a kit with a new design pump that does not come under the SB.
They do not have the STC so you will have to execute a form 337 and get approval from a FSDO.
The seal is of superior manufacture and design and does a great job of keeping water out of the acft even when deflated.