I've got most of the ones mentioned (Joy Lankom etc) but I can't resist 2nd hand bookshops and have got quite a collection now on all things gardening from Fuchsias, Cacti, CHrysanths, Dahlias & Veg. I enjoy reading about the old ways, I guess it's cos it's how my dad did things.
One favourite is Practical Gardeneing & Food Production in pictures by Richard Sudell. Cost £2.50 and if ever you want to know how to disguise your air raid shelter as a rockery, I'm your man
I also got a pen & pencil set off Geoff Amos for this as I wrote to him to see if he knew how old it was as there's no publish date and It was letter of the week in Garden News !!!