When I found out that Seneca Foods had discontinued their "Aunt Nellie's Old Style Sauce" which they had acquired from Shedds, I Googled it and found this. It's an attempt to recreate something similar to the sauce. I HAVE NOT TRIED IT, and I doubt it will be very close - the ketchup, paprika, and oregano all seem unlikely to me. What the hell.
1/2 cup good quality
2 tablespoons horseradish sauce
2 teaspoons good quality ketchup
1/4 teaspoon paprika
1/4 teaspoon salt
1/8 teaspoon dried oregano
Dash black pepper
Dash cayenne pepper
Combine all of the ingredients and refrigerate.