The black butyl sealant is sold in small tubes at most auto stores; otherwise it's only sold in caulking gun type tubes at body shop supply stores.$$$
I bought a small tube and reattached a rubber strip on my windshield. You'll need to come up with a way to hold the strip tight to the MH until the sealant cures.
I pulled up close to my garage, applied the sealant under the strip, then wedged a short board between them to hold it tight until the next day.
2000 Winnebago Ultimate Freedom USQ40JD,
ISC 8.3 Cummins 350, Spartan MM Chassis. USA IN 1SG 11B5MX,Infantry retired;Good Sam Life member,FMCA." My fellow Americans, ask not what your country can do for you, ask what you can do for your country. John F. Kennedy