'78 Gas tanks

[The X Man]

I'm looking at a '78 18. It had a funny smell, kinda like turpentine, in the ****pit when I removed the cover, but no gasoline smell in the engine compartment. I'm wondering about the integrity of the tank. it looks like the tank is aluminum, but it is definately the original tank. The seller just took it out of storage, had it commisioned at a marina and never noticed the smell before. what do you think? loose fitting, sending unit gasket? Are the tanks in a '78 an issue?
Thanks

[gcarter]

It COULD be any of your suggestions. And it wouldn't be hard to eliminate all of them.
If, however, it is the tank (and they don't last forever), here's a '60's 18 I changed the tank on.

http://www.donzi.net/forums/showthread.php?t=49388