Re: any upcoming issues?
I don't think you'll see problems from the storage itself - boats are fine on stands. But you'll see plenty of problems from the neglect 15 years on land indicates.
Learn about deck core issues - they are one of the largest problems on fiberglass boats. Fiberglass is essentially impervious to its environment - but the wood used in fiberglass boat construction is not. Good luck. Post pictures.
1979 Contessa 26