In the film “Of Love and Shadows”, based on an Isobel Allende novel
about Chile in the ‘70s, the hero’s father, a civil engineer who fled
Franco’s Spain with only his slide rule, passes it on to his son when he
in turn has to flee the Chilean dictatorship. It appears to be a simplex
rule in a green cardboard case, so could be one of several makes.
Cyril Catt