My underatanding of the 6" Jet Pilot history is that Marbles did the design which was accepted, and factory and Gladstone giddy with pride. Then the contratct to produce was given to Camillus which bid lower per unit, and after a lot of hard feelings, Marbles decided then and there to never bid on a govt contract ever again.

This still does not explain a grandfather owning the knife who died either before the knife produced or just at introduction. The 1958 knife was brass handled?