I have seen a lot of references in the Railway press and various forums (including this one) to the "Ferret & Dartboard" crest on BR locomotives. These almost always refer to this as being the later (1957-on) crest used. I have always thought that it was actually the earlier crest that was referred to as such in steam days. I think I now have evidence that I am correct. I attach a photo of a page from the August 1956 Trains Illustrated, announcing the "new" BR crest. This article clearly refers to the early emblem as the Ferret and Dartboard.