The Nikon Diaphot is an inverted biological research microscope circa the mid-1980's. It was the instrument used to create the world's first test-tube baby. With long working distance condensers, tissue culture and manipulation is possible from the top.
The original manual can be found here. The manual for the epi-fluorescence attachment is here. The manual for Differential Interference Contrast equipment on the TMD is here.
I am unsure what the "TMD" stands for, but my guess is "Total Microscope Domination"! The thing really is a beast!
To see the internal components and how it is assembled, I have done that here.