You don't know of any tripe shops! Lancashire at least used to be littered with them. My first full summer job was working for UCP (united Cattle Products) in one of their restaurants. Downstairs was a shop that sold different kinds of tripe and offal and upstairs was the restaurant where we had a least 3 kinds of tripe available on the menu. This was in 1969, it kept going for several years after that. We used to have battles with the tripe and if you've never been slapped round the face with 2lb of thick seam you've haven't lived !