My brother owned hull number 1 for several years. She was factory finished in teak--absolutely beautiful. She was a wonderful sailing boat. She did have some core saturation in the cabintop--mostly from the traveller bridge mounting bolts.
Re: Bristol 29
Point of fact: all Bristol Yachts were built with cored decks and cabintops, the core material was always end grain balsa. No Bristol ever had solid glass decks.
I would definitely get a survey before purchasing.