This is very close to the seasoning used at the famous Bookbinder's in Philadelphia.
1 1/2 tablespoons celery seed1 1/2 tablespoons salt2 teaspoons cayenne pepper1/2 tablespoon dry English mustard (Colman's)1/2 tablespoon whole thyme1 tablespoon paprika1 teaspoon freshly-ground black pepper1/2 teaspoon dried ground ginger2 whole bay leaves, crushed
Grind all ingredients in a food processor. Store in a covered container.