Hi Jim,
I've been using 3/4" by 1/4" foam weatherstripping from Home Depot
to seal my cockpit floor. It's cheap and you may have to renew it
every year because it compresses.
I've got a Gusher Mk 10 mounted into the port seat, by the
traveler. I'm thinking about moving that to the cockpit floor
(forward by the bridge deck) to have a unrestricted seat on port. I
like to lay down when cruising

.
Chris