Here's the section on the microscope and surgical camera from RCA's "Color Television Manual for Technical Training" (2nd ed., 1959)
More about the TK-45 can be found at
http://www.oldradio.com/archives/hardware/TV/RCA-TV.htm
The sensitivity of this camera was pretty terrible. Suitable for operating theaters, perhaps, I think the microscope version would have overheated any live specimens, but may have been OK for stained slides.
I remember the one at the Museum of Science and Industry in Chicago was brightly lit by a long row of PAR bulbs behind the valence. The lighting was at a high angle, which made people's eye sockets look like two black holes. Even with the high angle, it was nearly impossible to look out and actually see yourself on the monitor. Also, the background mural would show through anyone who didn't stop for a few seconds, due to the high lag of the vidicons.