Free 1996 35’ Gulfstream Innsbrook.. worth it?

Spend a little time doing up a real estimate of materials and costs, then add 15 -20% for unknowns. A guesstimate on this type of project could be way off.
That also is a large trailer. You got a truck that can pull it? And is it even pullable?
I spent over $2500 on converting a 14’ cargo trailer into a camper. And that was mostly just the interior, with a few upgrades to the outside.