It appears that in March 1974 two imposters took O.U.C.C.'s noble name in vain to get permits and keys for D.Y.O.
Unfortunately they needed rescuing...
Nick Coghlan's reply is, I regret to say, so far missing, but the first (upper 3 sheets) and second (lower page) letters from S.W.C.C give a good idea of the shenanigans.
Click on the images for enlargements.