Bits 'N Bites/ Nuts 'N Bolts

I make this every Christmas as it is makes terrific gifts. My children are always asking me to make them. Everyone comes back for more! It took many tries to get the recipe just right for us. Most have too much salt. Everyone agrees that this is the best!
**Please note that a smaller version is in brackets.

1 med. box Cheerios (4 c.)
1 med. box Shreddies or Wheat Chex (5 c.)
1 med. box Rice Chex (4 c.)
2 lb. Salted Mixed nuts (1 1/2 c.)
1 large pkg. small Salted Pretzels (2 c.)
1 small Box cheese stix (1 c.)

1 lb. Margarine (1/2 lb.)
6-7 Tbs. Worcestershire Sauce (3Tbs + 1 tsp.)
1 1/2 Tbs. Garlic Powder (2 tsp.)
1 1/2 Tbs. Onion Powder (2 tsp.)
1/2 Tbs. Celery Salt (1 tsp.)
2 Tbs. Seasoning Salt (3 tsp.)

Preheat oven to 250.
Mix the cereals, nuts, pretzels and cheese stix together in a very large bowl or pot. Melt the margarine in a pot on fairly low heat. Add in the Worcestersire and seasonings and mix well. Put about 1/2 the cereal mix in a large roasting pan and spread with half the sauce. Cover with the rest of the cereal mixture and then spread the rest of the sauce over. Mix well! Put uncovered in the oven. STIR EVERY 15 MINUTES! Bake for at least 1 hour. Should be done but test for taste and crispiness. Will crispen even more when cold (if it hasn't been eaten by then).