42mm black Helios-44 on Zenit-B

Ran into some interesting lenses lately.. from what I understand the Helios-4444 were 39mm and Helios-44-2 were 42mm threads...

A fellow collector in UK found an export Zenit-B with a KMZ Helios-44 with 42mm and I found an export Zenit-B with a MMZ Helios-44 42mm. Cameras are 1968 and 1969

Anyone can shed any light on this?

Thanks,
Vlad

Vlad,
there were both versions of Helios-44 in the late 60th: 39mm and 42mm.
I have two cameras Zenit-E from 1966 with black Helios-44 42mm.

Regards, Alexander

Yes, I can confirm. I also have Zenit-E from '66 with M42 Helios-44.