Hi all! Quick question, I just picked up a old sears craftsman jointer locally and I want to pick up a set of knives. When I went on Sears parts .com I got no response but the previous owner said that the knives were fairly interchangeable. It is a craftsman 6-1/8" 3 knife jointer, cast iron throughout, if I had to guess maybe 30yrs old. Any thoughts on the knives? When I look at them on amazon they all look the same to me. Thanks Kevin