Schrade made knives for Sears for many years. While they were a preferred vendor for Sears, they were not exclusive suppliers. Buck, Camillus, Case and several others also provided them with knives. The "Old Crafty's" were, I believe, SFO Schrades exclusively. Sears buyers had a habit of asking for upgrades on their Schrades. Early ones might only have a blade etch added, later different handle materials, and guards on fixed blades, and Sears, J.C. Higgins, Ted Williams, or Craftsman tangstamps replacing the Schrade tangstamps. There are some Sears knife collectors out there. I cannot give values on Sears marked knives, but they do add interest to a collection of Schrades. I have quite a few fixed blades with Sears markings, and several f..f..folders.
Codger