Something I discovered when cleaning my first shutter/aperture assembly (Canonet G-III): after soaking with naphtha of your choice, the liquid will remain between the blades a lot longer than it does where it is exposed to air. Capillary action and surface tension *may* act to prevent motion of these blades until the liquid evaporates. I thought I had wrecked the mechanism. Waited a (seemingly long) time and they freed right up.

If Micro-tools doesn't have it, try a "General" brand vernier caliper and a divider set from Amazon or some cheap tool importer. Grind the points down with a Dremel tool to fit whatever it is you're trying to loosen. Worked well for me.