This ad for the 514D appeared in the July 1951 issue of Proceedings of the IRE.

 

This ad for the 517 appeared in September and October 1951.

 

This ad for the new Sunset Plant appeared in the November 1951 issues of Proceedings of the IRE. Click on the image to view the PDF.

 

This ad for the 517 appeared in the December 1951 issue of Proceedings of the IRE.