I am thinking of ordering an "off the shelf" mainsail for my 1982 Catalina 27 from Airforce sails. Has anyone had experience with Airforce?? I also am unsure of what number to place on the sail, the current sail is not the original. What number is supposed to be on the sail? Does it have to do with the hull #??Present number is 77578. Appreciate any help you can give me.