The KE-7A is a specialized black chrome M4 made in 1972 by Leitz in their Midland Canada plant and offered in a limited run of 505 pieces for the U.S. Army. 460 of those units were acquired by the Army. Where the remaining 45 civilian pieces went is unclear.
KE-7As were fitted with modified shutters to operate in temperatures to -20 degrees Fahrenheit, were dust sealed for military field conditions and made to withstand explosive concussion (i.e. bomb blast). The 460 military versions were engraved to indicate that they were standard issue US Army property ( specifically, each with FSN (Federal Stock Number), Cont. (contract designation), and U.S. (United States) markings) and came supplied with a Leitz Midland made 50mm f2 “Elcan”. The Elcan 50mm f2 (“Elcan” being a contraction of “Ernst Leitz Canada”) was constructed of 4 elements for minimum size for military use. Where the “KE-7A” designation comes from is anyone’s guess.
In 1972, the M4 had been discontinued and replaced by the M5. I can only assume that the Army had placed its order during M4 production and Leitz were committed to provide a camera based on the M4 design. As with all assumptions, this may be wrong.