I now have a trio of them, M39, M42 and Kiev/Contax B. All are giving great pictures, however the M39 could need a cosmetic tuch up. (old aluminum barrels dont look too great.)
As for hoods I'm to found of Olympus 85/100 in stiff rubber.
Comparing them with my CZJ and CZO leavs not only me in doubt of witch is witch. My ZO OM 2/85 is in the same class, since my CZJ is uncoated it behaves quite diffrent with the big lamp in the glass.
A very recomendebel lens, and very cost efficent too....