If your description is accurate that the leak has been an ongoing problem and they previous owner just kept slapping a band-aide on it....it probably needs a whole new roof. Once water gets in, it tends to spread and rot well beyond where you find the leak.
On a 44yr old RV, paying for a new roof is likely more than the RV is worth.
I see a few options:
- Keep putting band-aides on it and string it along as far as you can.
- If you are handy, you could tear the roof off and rebuild it but it's likely to be a big project. I wouldn't try it unless you have experience, which it sounds like you don't.
- Sell it disclosing the issues but it likely will sell for next to nothing.