Camera with an “... / MANUFACTURED BY / GASTRO-PHOTOR LABORATORIES /NEW YORK, N.Y. /.../...” inscription, manufactured in the 1940s and used to photograph stomachs for diagnostic purposes. Frank Gerhard Back (1902-1983) was a Jewish mechanical engineer from Vienna who worked for Wolf, manufacturer of endoscopes, and moved to the United States in 1939.
Ref: “Candid Camera Photographs Interior of Human Stomach,” The Science News-Letter 37 (June 8, 1940): 356-357.
Franz G. Back, “Motion Picture Camera,” U.S. Patent 2,297,603 (Sept. 29, 1942), assigned in part to Gastro-Photor Laboratories.
Nick Hall, “Frank G. Back and the Postwar Television Zoom Lens,” Technology and Culture 57 (2016): 353-379.