The T* lenses are excellent. My 120 macro is the sharpest lens I've ever shot with. I have a 500CM and two lenses.

To answer your question, I found this information on another forum in an old post:

500C was first model that had Compur (leaf) shutters in each lens. 500C body focusing screen can be changed only by a technician.
500CM is essentially identical to C except screens are use-changeable.
501C and CM had a slightly different mirror to avoid image cut-off with long lenses.
Backs, finders, lenses, etc., etc., are all compatible with all these models.
Earliest lenses were C lenses, with coating on internal surfaces only. CT* lenses are multi-coated and have a slightly blue apperance. According to Wildi and other authorities, the C lenses perform perfectly well if you use a hood.

There is some confusion about the mirrors used in Hasselblad bodies.
The first body in the 500 range, the 500C has a mirror that is too small to prevent vignetting when using longer lenses like 250 mm and longer. With some macro applications this problem can also occur.
The 500 CM and the 501C are for the most part identical to the 500C but have user changeable focusing screens that do not need adjustment as the 500C does when changing screens.
Also the 503CX and the 503CXi still have the small mirror

All "F" bodies like the 2000 and the 200 series have large
mirrors that do not have the vignetting problem.
The 2000FC was the first model from Hasselblad to be sold with the larger mirror in 1977.

From the 500 series the 501CM, 503CW, 500ELX, 553ELX, 555ELD have the large mirror.

Ill add a few nuggets I learned. Some Hasselblad 500CM bodies from early in their changeover from C to CM have odd things about them.

My 1974 (S# UI 1522**) 500 CM shared the reduced small mirror that causes the mentioned light cutoff to the focusing screen with the 500C

It does have the quick change tabs for the screen though.