Without doubt and/or unquestionably a Demo knife.
A Demo Knife or 4 blade scout/camp knife has been part of my EDC pretty much every day since April 06, 1960, when one of my uncles gave me the (first?) one the Army issued him for my 5th birthday, while home on leave between a tour in Viet Nam, and a tour in Germany.
(sadly, that knife vanished (along with a lot of my other stuff that my mum trashed or gave away) when my mum divorced my pop, in 1966)
The oldest Demo I have is a Western made, issued to me by the Army Reseves, in 1975. (no picture; it is in my cigar box, over at the Assisted Living facility's owner's place until after the state finally gets around to inspecting here).
The Western made is almost identical to the Marbles MR 278. The differences being:
(1) The Western is 1/16 inch longer closed than the Marbles.
(2) The Western has "CAN OPENER" stamped on the can opener blade, whereas the Marbles lacks that blade identification stamp.
(3) The Marbles has match strike nail nicks on all four blades, and has "MARBLES" etched on the main blade.
(4) Different tang stamps. ("Marbles" vs "Western")
(NOTE: Only one blade per spring is opened half way. I have no use for, nor any desire for, a busted backspring.)
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