Bayfish,
In '79 the stringers were glass-encapsulated wood. We didn't go to completely composite until '96.
If the seller will let you, drill a 1/4" hole into one of the stringers in the bilge area. When your bit comes out, it will either have wood shavings on it, or it will have some indescribable black mush-like crap on it...
If the latter, pass...
