Preheat the oven to 250 degrees. Heat margarine in large shallow roasting pan in oven until melted. Remove, stir in the seasoned salt and Worcestershire sauce. Next, add the Chex and Cheerio cereals, pretzels and nuts. Mix until all pieces are coated. Bake in the oven for 1 hour, stirring every 15 minutes. Spread on absorbent paper to cool .