hello and welcome!
Yes the seals for windows are available, look into Inland RV, Out of doors mart, and others to find them. I like/have had good service with Inland. Re-caulking is a necessary job on these trailers. I use a good tall wooden ladder and can rear the center. I usuallly have someone holding the ladder if I am stretched out over the roof. They say you can walk on the roof ALWAYS stay on the rivet lines, and NEVER on the endcaps. I myself cannot bring myself to try it. I have had very good luck repairing the tamboor doors. New material is available, not a perfect match (some of my doors had been done by PO)and it's not cheap. I used carpet seaming tape, the kind you heat with an iron. I removed one door at a time keeping the door in proper stacking order, and used 4 strips of seam seal almost to the ends, and two in the middle. I am pleased to say that so far they are working pefectly. OK, now the best part, we love pics, so can you share some with us? You reallly want to take them to document progress antway. Cheers, John