Hi!
What a wonderful lens! I've wanted one for ages, finally found one I could afford. Unscrew the rear group, blow the dust out, like new!Samples: http://www.donsauction.com/PDML/24_28.htm
Don, that's one of the few lenses that does not necessarily have to be replaced with modern (24/2) optic... It is w o n d e r f u l.
Congrats. Boris