I don�t think that�s quite accurate, Keiva � I can think of plenty of examples of cockney that work the other way about, such as �apples and pears� for �stairs�. Like most argots, the key is to draw a line between the insiders and the outsiders.

I am inclined to think you have hit the nail right on the head, sunny Gym � the original term would have been something quite pompous and officious like inflatable vest for which the substitution of �Mae West� would have been a natural inflation. To put it in context you have only to imagine the class-ridden system of England in that time: if the educated officers introduced new equipment with a fancy name, it would be imperative for the ranks to make it their own by a linguistic twist. But Rhuby is more expert on CRS than I � come on in, Rhuby, the water�s quite buoyant!