They were marked in different ways at different times. When the company was vibrant and healthy, they had their knives made with only their own company trademarks. As the markets and the business changed, so did their specifications for their knives. Sears went through similar evolutions. Sometimes they sold maker branded knives, after years of ordering only knives with their own trademarks. Then they added etches of their own design to stock production knives. And then Sears went back to exclusive features and markings. Often looking at the knives in their catalogs tells us when the details changed. It is not a study I've had the time or funds to undertake.