Neither Case, Western nor Cattaragus ever had a contract for the USN MK-2/USMC fighting/utility. KA-BAR, Camillus, PAL and Robeson Shuredge were the primary ones during WW-II. Case made an extremely small number of prototypes but it never went into production.
KA-BAR has never had a military contract for the knife since WW-II, all recent knives have been for commercial sales.
Conetta, Utica and Ontario all had contracts for the knife in the post WW-II years.