I have a new 76 31ft
Sovereign and I discovered a leak in a plumbing vent (there are 3 of them). I removed the cast aluminum cover and discovered the problem....cracked/split/deteriorated seal and lots of decayed trash. Cleaned everything out and realized that I was probably looking at the original stuff, 30 years old! Looked at Andy's on-line offerings, seals and fiberglass screens, for $6.50 each, plus shipping (I need 3). Decided to do a little LOCAL shopping. Discovered that LOWES has a 6"X6" piece of red rubber , 1/8" or 1/16" thick, in the plumbing dept, that is perfect for making the gasket. The hardware store gave me a 6" wide strip of aluminum screen. The aluminum is better than the fiberglass in that it can be cut and molded to fit in the "TOP" of the cast aluminum housing (use a little Vulkem to hold it up there) thereby preventing trash from ever getting inside and clogging the drain holes in the aluminum casting. You're welcome, Bill