Daniel,
thanks very much for the filter tip on the Zenitar!
Another find,
which I did not know about,
there was a soviet Nikon F2 copy with PK-mount!
This was called Xalmaz, and here is some more info on soviet PK-mount lenses,
Rare soviet lens(PK-bayonet) list 13.01.2008
The reason why I was looking it up is an MC Volna 1.8/50 (also has the 'Lomo' name on it, all in cyrillic letters) in PK-mount that fell into my hands.
MC Volna/Lomo 1.8/50 + polarizer on K100D, no pp
MC Volna/Lomo 1.8/50 on K100D, some pp
That is the fleamarket stand I got it from, really hard to resist once you get sight of it. I should not go there anymore :-)
The lens itself seems to be hard to focus, which I am hoping is due to the fact that it's got lots of microcontrast - another good portrait lens, will post portraits if I get permission, we'll see.
All the best,
Georg (the other)