Tripe was eaten by most people in Lanacashire in and before the 30s, through WW2 and into the 50s certainly. UCP shops, which often included a restaurant, were owned by United Cattle Products Lt d. They had shops in many Lancs towns. Types of tripe included 'seam', 'honeycombe' and ''slut'. I seem to recall that slut was blackish. They also sold cowheel, trotters, pigsfeet, all very similar really and also 'elder'. That was cooked cows' udder. Delicious with vinegar, salt and pepper. All this offal was cheap and high in protein. It was a useful item in the diet in hard, low pay times. And I do love tripe and onions. Ie. Honeycombe or seam tripe cut into about 1" square pieces, stewed gently in milk, with chopped onions. Best wishes Bill