Primrose was an extensive line of separators from International Harvester Corporation, meshing, it appears, with the McCormick Deering line. The sizes range from 350 pounds per hour to 1100 pounds per hour. The first model had a round supply can with a flat bottom, style E, which switched to style B, S, and R, with a round supply can. Color is blue; there may be some a different color, however.