Add 2 quarts of water to a medum stockpot and bring to a boil. Add macaroni and cook until it is al dente, approximately 9 minutes. Do not overcook the pasta or it will fall apart when the salad is tossed together. Rinse macaroni until cool. Drain well and let it dry out slightly.

Add pasta to a large bowl. Carefully fold in celery, onion, cheddar, Swiss cheese, Parmesan, dill pickles, salami, and black olives. Refrigerate the mixture, uncovered, overnight (or refrigerate for at least 2 hours).

Mix the Lowry's garlic salt, minced garlic, horseradish, white pepper, black pepper, cayenne pepper, dry mustard and celery salt together. Add to salad. Fold in the pimentos. Fold in 1 cup of mayonnaise to start. Add up to 1/2 cup more of mayonnaise if needed. Refrigerate again for 30 minutes to 1 hour.