Some of you may recall my rapturous post running victory lap etc ..cough cough!! Well I went to this today, and wanted to test fire it and considered even loading it.. I fired it...and once again very sticky Grr!! I don't think it's the cold !! Grrr!! This is the result of using Naphta to loosen up the focus and all that dissolved grease ended up in the shutter. The first time I stripped and cleaned it, the re-assembly was badly done and the seating of the lens in the body was pinching when focused at infinity and after a week or so it was also again sticky. So I took it down again and spent three hours cleaning the shutter blades meticulously, using a whole bag of cotton swabs. I spent more time on the re-assembly and I got it right... that's when I foolishly claimed victory. I shot two rolls through it one B&W and one color with acceptable or expected results. I don't trust myself to tear down the Prontor SVS shutter mechanism. Some of us are trusted mechanics.. I'm scared I'll really screw it up to the point it'll never be anything but parts... I'm considering flushing the shutter profusely with Naphta and/or soaking it for awhile. I considered this before, but took the conservative long meticulous route with the swabs for fear of harming the lens coatings. IIRC I can't remove the middle element. I was able to reach only one side of the shutter leaves, but I was able on bulb (B) to access and safely clean the front of the middle element. I haven't torn it down yet, to see this closely. Maybe I can find a level of fluid that covers the shutter but not the glass?? But my question to the forum is how bad is Naphta on relatively modern coatings? Will the lens coating dissolve if soaked in Naphta ? This was from the last time before I removed the shutter, I believe you remove the back ring and the whole assembly comes out. Then you can remove the rear element and ..The End!