This cold war calculator came from a State of Montana Surplus Property Depot. They got it from the Department of Disaster and Emergency Services [formerly the Office of Civil Defence]. It appears to have been produced in 1967 by the South Western Division of the U.S. Army Corp. of Engineers. It is made of stiff plastic and is 170mm x 220mm. The back is blank.
It is a very rare cold war calculator and I know nothing else about it.
For more posts about Cold War calculators click on the Cold War Calculators category on the right.