I have always suspected that these were made for Western by Camillus for some reason unknown to anyone still alive. The MIL-K-818 never appears in any Western catalog as being for sale. The 1975 "catalog" was simply a 4 page brochure that includes a picture showing a display of all Western knives for that year and a MIL-K-818 is not included in the mix.
Possible. But where would the profit be? Western
had to submit a bid to the government/military to manufacture x number of knives for issue. If they were (presumably) low bidder, since they got at least one contract, contracting Camillus to make them would result in a net loss for each knife.
It
might also be possible (likely?) they were made by Western, with the entire production for the military; with none for the civilian market. (possibly to appease Camillus, who did sell the Mil-K-818 (Model 1776 designation on/for the civilian version. The USMC stamped version was the Model 1778, I think) on the civilian market, along with the TL-29.?)
I'm pretty sure Colonial and Case also made both the Mil-K-818 and TL-29 for the military, to the required military specifications.
Without doubt Camillus made the majority of those issued, but they were not the only one to get the contracts for the two knives during the years they were standard issue.
I know I got the Western knife from the Army Reserves, in 1975.
The only "Demo" knives I've ever bought are the $6.⁹⁹ SMKW Marbles version, one in the 20-Teens and one in 2021 (so I wouldn't have to carry the "old" one, and to have a spare/extra). The only differences between the Marbles and the issue knives are no "CAN OPENER" stamp, and Match Strike pulls on the Marbles. Oh, the Marbles is also a hair shorter overall length, but the blade is the same length.