Welcome to the site. Nice to see you here.
It sounds like "someone" did a conversion and probably only used 2 hinges where it originally had 3. Many times when a top was chopped one of the hinges would be eliminated also.. As far as adjusting, without pictures I don't know how to answer that. If some kind of kit was used, like a hidden hinge kit, then maybe.. You'll really have to see if the body is flexing or the builder just didn't adjust things properly.