It was meant in an endearing way. My mother used to tell me that I could n't go out wearing certain clothes cos I would look a right 'clip' looking back at some of my photos I know what she meant !
You know how lovers of heavy metal tend to wear black and have their hair long and 'mods' would dress in union jack jackets and pink ankle swingers. Acker Bilk lovers would have daft little beards and even dafter waistcoats and George Melly would have some barmy suits and how the Beatles inspired loads of different styles and if you saw anyone out wearing Sgt Pepper gear or even a beatle jacket with perhaps a Dave Clark five shirt they would probably look 'a right clip' Well John seemed to encompass everyone of those at once.You certainly could n't 'pigeon hole' him. It was probably his jazz influence along with his diverse musical taste.
I mean this in the nicest possible way but ... most lovers of jazz look 'a bit of a clip' anyway, I think it goes with the territory.
all the best Ralphie and regards from Ritchie ( who at nearly 50 does n't give a damn )