Prepare the meat loaf. In a mixing bowl, place the ground beef, chopped onion, crushed crackers, ketchup, Worcestershire sauce, and egg. Add seasoned salt and pepper to taste. Mix well, using hands or a spoon. Form into loaf and place in a greased 8" baking pan.
Prepare the potatoes. Wash the potatoes, pat dry, puncture with a fork in several places and lightly coat with a thin layer of shortening or soft margarine. The coating will make a crisp potato skin.
Prepare the winter squash. Cut acorn or similar size winter squash in half lengthwise. Scrape out the seeds and pulp and rinse well. Place the squash cut side up in an 8" baking pan. Place one tablespoon of butter or margarine in each squash half. Pour about 1/2" of water into the baking pan. Cover pan with aluminum foil.
Preheat oven to 350 degrees. Place the pans of meatloaf and squash into the oven. Place the potatoes directly on the oven rack. Bake for 1 hour.
To serve, remove the meatloaf from the pan and slice. Slice open baked potatoes and add toppings, if desired. Remove squash from the baking pan.