Question Author
Spot on, Spotty.
It was such a rare sight. People just don't whistle anymore, largely because most modern music is tuneless, I suppose.
I'm knocking on a bit now and in my younger working days whistling when one was busy was a sign of happy contentment, as you seem to suggest, Marcel.
Cheers. D.
PS. I've just had a go and managed to whistle Land of Hope and Glory right through- but I had to wet the whistle, first .
Thanks for your answers.