I bought a lot of jazz records from Acorn Music, based in the West Country - I think it was Looe, Cornwall, but I'm not sure. Are they the shop discussed in the book? What happened to the owner - I'm talking about the 1970s/1980s.
I wonder if it is a different 'Acorn'. Acorn Records are based in Yeovil, Somerset, although I think they did have a second outlet for some time (short lived) in Weymouth, Dorset. The owner of Acorn is called Chris Lowe (the other founder, Rob, sadly passed away back in 1995).
It might not be the same. The Acorn shop I'm talking about moved south from north Devon to (again, if I remember correctly) Looe. I heard a rumour years ago - after I'd stopped buying from them - that the owner had died. I don't remember his name. Their main business seems to have been mail order.