40 Stalks Celery
10 Small Cucumbers
20 Green Peppers
10 Med. Onions
5 Cups Black Olives
10 Cups Cubed Swiss Cheese
20 Tomatoes

Cut into bit size pieces.

Dressing:
15 Cups Salad Oil
7½ Cups Vinegar
10 Cups finely chopped onion
10 Tsp. Salt
10 Tsp. Minced Garlic
20 Tsp Crushed Peppercorns
10 Tsp. Rosemary leaves
10 Tsp. Basil Leaves
10 Tsp. Oregano Leave

I never actually weighed out the stuff before, but if you are making for 175, you are probably purchasing by weight, so here goes.

Normally, this would be for 1 person, it is a plateful. You could use the same amount for 2 people since you have other salads, and it is basically a side salad. (A.mounts in parentheses for your shopping list)

3 ounces cucumber (15 pounds)
3 ounces ripe tomatoes (15 pounds)
2 ounces feta cheese, crumbled or cubed (10 pounds)
1 ounce bell pepper (5 pounds)
1 ounce red onion rings (5 pounds)
1 ounce olives (about 10) PITTED for party purposes (5 pounds)
1 ounce olive oil (use at least half real olive oil, please) (5 pints or 10 cups)
1 tablespoon lemon juice (5 cups)
oregano, garlic, etc to taste (your recipe looks fine, just do upgrade to olive oil)
OPTIONAL sprinkling of capers
few artichoke hearts
spoonful of garbanzo beans
sweet banana pepper rings or pepperoncini or roasted peppers
If I were adding celery, I would add about the same weight as onions.