Extract from OED Online

1961 J. FRANKLYN Dict. Rhyming Slang (ed. 2) 146/1 Dog and bone, 'phone... This term seems to have evolved since the second war, probably partly due to the increase in the number of telephones installed. 1989 Daily Tel. 22 Mar. 31/1 British Telecom brings to you the telephone of the futurethe dog and bone that offers self-improvement and self-expression. 1996 Sporting Life (Electronic ed.) 29 Aug., Yesterday, yours truly was just settling down with a crate of lagers ready to watch a Chubby Brown video when the dog and bone starts buzzing. 2001 Mirror (Electronic ed.) 6 Oct., Lazerbuilt Chic Telephone, £19.99... This amazing Dog and Bone is £49.95.