If I remember correctly, I got this recipe from a book by Dianne Mott Davidson, a mystery writer who wrote about a caterer and included recipes. People are always asking for the recipe!! I've added a personal touch here or there, but it's mostly the same I think.
These are my favorite deviled eggs! The ketchup makes them different from other deviled eggs, my family devours them! All the ingredients are to taste, I never measure, but tried to approximate. Feel free to adjust to your tastes.