I replaced my seals that were leaking by using a seal from Home Depot/Lowe's. I also moved the seal from the back, upright edge of the frame to the flat area of the frame in between the door closing and the frame so as to pinch the gasket instead to roll it off each time the door is closed.
2016 Montana 3790RD Legacy Edition
Onan, TST TPMS, TrailAir pin, 8k Disc Brakes
2013 F350 DRW 4x4 CC LB
Viair 10007, Ride-Rites, Westin HDx, 12k Smittybilt