Potato Salad (about 100 Servings)

I don't remember where I copied this recipe from, but... it's in my recipe box.  If you like the following flavors, this might work for you.  If not, use your own 'salad sauce' and just use the  list below to give you an idea on how much of the 'basics' is recommended for 100 servings.  My comments are in red print below.

INGREDIENTS:

• 40 pounds potatoes
• 5 cups finely chopped onion
• 20 teaspoons salt
• 2 and 1/2 teaspoon ground black pepper
• 5 cups Italian Salad Dressing
• 10 cups mayonnaise or salad dressing (like Miracle Whip)
• 1 cups chopped celery
• 3 dozen hard-cooked eggs, cut up

DIRECTIONS:

1. Wash potatoes. 
2. Heat water to boiling.  Add un-pared potatoes to boiling water.  Recently, while watching a program on Food Network, it was said that we will end up with a more evenly cooked potato if we start their cooking in COLD water and let them heat along with the water.
3. Boil for 30-35 minutes OR until tender (not mushy!)
4. Drain, cool and peel.
5. Cut potatoes into small cubes (or slices, or ??) and combine in bowl with chopped onion.
6. Sprinkle evenly with salt and pepper.
7. Add Italian salad dressing and gently mix well.
8. Cover, and refrigerate for at least 2 hours.
9. JUST BEFORE SERVING, add salad dressing OR mayonnaise.  Toss until the potatoes are well coated.
10. Stir in chopped celery and chopped eggs.
11. Refrigerate promptly and KEEP cold.