The white jacks seem to be early prototypes of the modern Zuckermann jack. The modern ones: the two side by side show tongues inserted the right way and the wrong way, front and back view. The other photos show how to thread the tongue so as to insert it correctly. I apologize for the fact that the interface for attachments doesn't allow me to place the photos in a logical order: they are numbered correctly, but the slide show will play them in reverse order.