Its not a British law I have heard of... and the alcohol thing comes from someone who lived in one of the Scandanavian countries but I cannot remember which one. It may not be a law so much as an attitude then.

Oh yes, most of the morals about nudity come from Victorian values (those wonderful hypocrites, the Victorians with thier casual brutality to the working class and a welath of perversion under the covers but an outward prudity that was almost ironclad ). As you said, laws once made are difficult to unmake and many of the public decency and sexual laws were made about that time (though buggery and sodomy were both ruled against during the Tudor period). They can be modified slightly but rarely undone save after a lot of time and effort.