Originally posted by fungiman_md but alas! three of the five screws will not open (using a watchmaker Philips screwdriver), am I using the wrong screwdriver, are stuck screws a known issues in these old (>30 years) lenses? what can be done to save this great instrument?
The screws on Japanese lenses are not Phillips-head. They are JIS. Do not try to force the screw or you
will strip the screw.
List of screw drives - Wikipedia, the free encyclopedia
You can buy a set of JIS drivers at micro-tools.com. You can also buy a lens ring to open the lens from the front.