The Bristol 30''s were nice little boats for their day. These Halsey Herreshoff designed sloops were a part of a series that included a 34 footer and a 26 or so footer. I would not call these "traditional full keel cruisers" by any stretch of the imagination. They were really fin keel boats with keel hung rudders. In terms of sailing ability this hs neither the tracking of a full keel or the advantages normally associated with a fin keel and spade rudder.
Still and all these boats offered good performance for their day and were know as pretty nice sailing boats. They were offered both as a fixed keel or as a centerboard boat. Both had their own advantages.
They had a bit of an unusual layout with the galley occupying the length of one side of the cabin and a settee/berth occupying the other side. It made for difficult lounging and chatting or bracing when cooking under way.
Bristols of that era tended to have acres of wood grain formica for bulkheads and flats. Beyond the obvious low maintainance and questionable aesthetics, formaic laminated bulkheads can be problematic because they can rot out without providing any clues that deterioration is taking place. Your surveyor will need to play especial attention to this issue.
Another area of concern would be the encapsulated keel. Some of the Bristols of that era used steel punchings set in concrete. While I know this to be true of the Bristol Corsair, I am not sure if this is true of the Bristol 30. In any event it is important to check to see if the keel is still laminated to the ballast.
Lastly this boat sounds like it has had extensive core work performed. I would investigate that carefully as it is very difficult to get a repair
that has the same appearance, weight and continuity of structure that you would expect in a boat that had never needed a deck job.