When I bought it, the seller on ebay mentioned fungus. In a short YouTube reseach expedition (2 video's) I found out anyone can remove fungus from a Sowiet Union era lens. Hybris is my middle name and I was very lucky to still have a lens after removing the fungus.
Now I have to learn to get the best out of this 'Nightvision' Sowiet Army lens, called Helios Cyclop. The one with the weird bokeh, no aperturering (f2 only) and which I use with a adjustable macroring. That ring can give me macro and infinity without changing anything on my camera.
I hadn't expected this lens to function so well. Evertytime I look at it I'm glad that I dared cleaning it.