Robomatic - that was Cary Grant, not James Stewart in "Arsenic and Old Lace". I though his performance defined "overacting", but otherwise it's a great movie.

There's one movie that may have gotten wider distribution in the UK, but I never heard of it until it showed on video here in the states -
it's called "The Emperor's New Clothes" - not the HC Anderson tale - this one concerns a plot to smuggle Napoleon off of St. Helena after replacing him with a look-alike. Everything goes wrong, and eventually ends just right. I think it stars Ian Holme. I get all the Ians mixed up. It stars the same Ian who played the priest in "The Fifth Element".