Here is one source:
Seals : AP Products, RV/Mobile Home Hardware
PPL, Amazon, Dyers and Tweetys are other good sources.
Seals can be 3m tape mounted, screwed on, pop riveted and clip on. You should take a cross section measurement to match it.
Welcome to Lake Wobegon where Justin and David utilize abductive reasoning to help solve F/SS issues.
Happy Trails and Remember the Pequod.