That's it! I knew it looked familiar. Curly maple, "flame" maple, "burl" maple...Whatever you want to call it, it sure looks like one of the "trio". Ya' know how unusual that handle was back in that time period? I would venture to say it was unusual enough that the chances are more than just "good" of your model #5 and "my" #5 being one in the same!
I know the guy I sold it to has listed and sold some of his knives on ebay. The "N.W. couple" could have picked it up from him...or from the person who got it from him...or the person who got it from the person who got it from the person or the....OK: You get the idea. It's a small world, this "Randall thing", and a lot of them come back around...Nice knife!
Best, Capt. Chris