I've spent months looking for it and I'm getting to my wits end, if anyone has seen ore even heard of this book then please let me know. It's "Fly Fishing" by J. R. Hartley.
If memory serves me right, due to the popularity i think they did make a book called Fly Fishing, due to its popularity on the advert!
EDIT:
J R Hartley was played by Norman Lumsden, and following the advertisements, the British Library and bookshops were innundated with requests for the book. Eight years after the adverts were first shown a real version of the book was ghostwritten by Michael Russel and published by Random Century. Its full title is Fly Fishing: Memories of Angling Days. Lumsden was hired once again to pose as the author - but this time of a real book.
I've spent months looking for it and I'm getting to my wits end, if anyone has seen ore even heard of this book then please let me know. It's "Fly Fishing" by J. R. Hartley.