I bought an M40-80 zoom that was infected with fungus. I bought this for a "project", it was cheap and I've wanted to take a lens apart. I've removed the first two elements and the rear and next two from the rear.. There was fungus on the first two, the and the rear. The two remaining elements have fungus between them, but none on the back of element four which is now exposed from the back. The aperture blades are behind element four and are very clean and snappy. Element three appears to possibly be threaded, nothing holding it in from the front. It may even be glued? I don't know how to get it out. I would prefer not to disassemble the other internal parts of the lens. Once three is out I can complete the cleaning and put the lens back together. Possibly these were assembled from the rear of the front barrel, but I haven't figured out how to remove that, it is probably fastened internally since there are no external scrws on it.
Anybody have any insight on this?