Have you tried contacting Heller, directly? They're called Heller Seasonings and Ingredients. Did you try an internet search? If you search on "Heller locker pork special", it comes up on the first try.
It's called "Locker Special Pork Sausage w/AO", available in 50 lb bags from Nassau Foods, Inc., of Brooklyn Park, MN. Ingredients: Salt, Dextrose, Red Pepper, Extractives of Clove, Sage, Capsicum, BHA (0.07%), BHT (0.07%), Tetrasodium Pyrophosphate and Soybean Oil added to prevent caking. Use: 0.50# seasoning per 25# finished product.
The Nassau Foods catalog on their website is a year out of date, and their Facebook page is two years out of date, so I don't know if they are still around, but their website is still up. You could also call Heller and find out about the seasoning, if it was discontinued, who distributes it, and if you can get it directly from Heller.