1952:
Hudes Merchandising Corporation
Hudes Merchandising - Swissair Navigator Circular Slide Rule
Rec. Num. 1 of 2
Source: Flight September 5th 1952
1953:
Hudes Merchandising Corporation
Hudes Merchandising Corp : Swissair Navigator Circular Slide Rule
Rec. Num. 2 of 2
Source: Aeroplane September 11th 1953
