Would u buy this TT w "repaired" water damage?

Personally I would pass on the trailer and use the time spent on thinking about the situation, asking for advice, etc. and be looking for a more sound option.

I believe if you have to ask about damage, a leak, possible rot, or anything related that you have your answer and that is to pass and continue to search.

You will definitely find something else and hopefully a nice trailer that has been well maintained and stored properly. They are out there.