David,

Wouldn't the simple solution be to check with your local police?

I wear a fake sgian dubh most times I'm out and about, and save the nice oxhorn real* one I bought from the Scottish Tartan Museum for dress up occassions. That way I don't ever have to worry about it. Truth be told I think hardly anyone ever even notices the handle's presence be it knife or bottle cap opener.

Cheers




* The blade while shiny and nice looking is best suited for defending one's person from a piece of vicious Brie or perhaps a savage bit of Stilton.