Newspapers call it the 'square mile of vice.' Few tourists fail to visit it. Football supporters 'up for t'Cup ' always seem to wind up there - in their cups. But Soho is being tidied up, threatened with replanning. 'Miss Whiplash' will have to find new premises - so will some of the restaurants, theatres, strip clubs, discotheques. But still there will be newspapers in 15 languages; cheroots from Burma; samovars from Samarkand. It seems impossible to consider Soho in any other terms than the centre of the British film industry; the London Orchestral Association; the meeting place of artists, sculptors, stunt men, wrestlers - and the stamping ground of Lord Longford's stern-minded committee. Soho is a place of character - full of characters. Frank Norman wrote a book about it. Harold Williamson, a Tynesider, has come to know and love it. Charlie Squires has always been fascinated by it. Now they have been there together.