the term "wank" has been current over here (UK) for quite a long time - I certainly remember using it at school in the '50s

Yes, Rhub, this is why I have a little trouble accepting the word as a recent Australian import (although how recent is obviously a moot point). You can't imagine kids - or most adults, at that - talking about "masturbating".

Maybe no-one in the UK talked about masturbation at all before "wank" was imported, although I find that hard to credit.

Ahem, for want of a better expression.