Cook the bacon until crisp, dry on a paper towel and crumble, now take off the shell from the eggs and chop. In a bowl combine the chopped eggs, celery, mayonnaise, salt and pepper and mix well, stir in the bacon. Chill to help blend flavours, then when ready to serve, layer lettuce, egg salad and tomato slices on 4 slices of bread, top with the remaining bread slices.