In article <33573D73.47D9@ra.msstate.edu>, sgr1@ra.msstate.edu says...

>How are these lenses different from normal Nikon micro-nikkors?

As I recall (a euphemism for, "I could very well be wrong
about this, but if so, I can blame my memory...!";-),
the differences are three:
-built-in ring-light (battery or AC supplies were available).
-no focus mount.
-diopter lenses were provided to adjust magnification.
I cannot recall (heck, I never knew...!;-) if there was anything
unusual about the diaphragm, or possible lack thereof...
Hope This Helps, aka, "David Ruether"...;-)