I have a 26' cruiser with a PSI surface drive installed. I am trying to locate a shaft bellows and seal for the unit.
PSI-aka "pulse drive" is , I believe, no longer in business. I might contact Twin Disc and see if they can help, as they produce and offer a variety of surface drive products.
Frankie Fruge at Schoell Marine should be able to help. Get in touch with her here.
This is the project Harry Schoell is working now. AFAIK they still support Pulse Drive.
That said, the seal for mine was easy to find, just a "normal" seal, check the number on it. If it is a 1500SS, I have some extra seals here.