Vintage Binaural Headphones

My uncle, who taught mathematics in Toronto's east end (Danforth Tech) for 35 years, was recently informed about my project on binaural recording and to my surprise dug out an old pair of headphones with microphones mounted in the specially shaped cups. Here's a link to some specific information regarding the specs of the cans.

Not sure if I'll get a chance to hook'em up and test them but it would be cool to benchmark these against the dummyhead I'm currently working on.