I'm sure there's no major damage. The MAIN thing about the alcohol is actually vapor lock during flight. Some of the rubber in the fuel system (o rings, fuel cap gaskets) might need replaced, but for only 5-10 hours of flying? I'm sure this plane is fine. Sounds like a killer deal.

Jeff Hersom N3740J '67 150G "Gremlin"
Hangar W-6, Helena Regional Airport
Places I have landed Gremlin:
[Linked Image from visitedstatesmap.com][Linked Image]