The last time I unfroze one of these, I set the shutter, lenses and all (couldn't get them out they were so stuck) in a coffee cup of 91% alcohol. 99% would be better, but 91% worked for me. After 4 days of soaking the shutter, and pulling it out once a day to give little taps to the side of the front element, it unscrewed w/ my fingers. Took a Q-tip to it, but there was nothing much to clean up. Worked perfectly. Before trying this, I had heated it, tapped it, used a gripper tool on it, etc and still no go.