We have a new to us GB Eastbay 47 FB. Took possession in late April, have about 50 hours underway so far (Connecticut to Chesapeake in April, and just last week Chesapeake to Maine). Our out of water survey (two days, about 12 hours total surveyor time), engine survey, and in-water survey/sea trial found no significant or structural issues. A few minor wear and tear mechanical issues (e.g., steering tie rod ends needed replacement). So, I can't point you to any issues / areas to pay particular attention to on this boat compared to other boats.
The one thing I'll say that has been very valuable to me is all of the original boat documentation was kept, including full schematics, as well as manufacturer info on every piece of equipment on the boat. Invaluable. (Also had full service records for past 6-7 years, length of prior owner's tenure.) And we absolutely love the boat.