I was thinking of doing the same this winter. Try this link.
http://pompanettellc.com/current-cat...-gasket-seals/
Also, here is another good thread, however most of the threads I found are regarding 23 Sceptres and 25 Seafari’s. I’m hoping the p/n is the same for our Seafari 20’s. I have been know to Macgyver things though.
http://www.classicseacraft.com/commu...ght=windshield