Drain and slice crab. Dice half of bread into bottom of large rectangular baking dish. Mix the crab, mayonnaise, celery, green pepper, onion and salt and spread over diced bread. Trim crusts from other 4 bread slices and place over crab mixture. Mix eggs and milk, pour over crab and bread. Refrigerate overnight or several hours. Bake in 325ºF. oven 15 minutes. Remove from oven and spoon undiluted mushroom soup over top of casserole, sprinkle with cheese, return to oven and bake 1 hour longer.