Some will disagree, but here's what I would try: soak the blades is lighter fluid, then while they are still wet, take some powdered graphite (use sparingly) and a Q-tip and very gently rub it on the blades. They should eventually loosen up, at which point you can apply more graphite and begin working the shutter. This will help to get the graphite (which will act as a dry lubricant) into the inaccessible parts of the blade actuating mechanism. After you've got it loosened up and the lighter fluid dries out, use a bulb blower to get any remaining loose graphite out before reinstalling the lens elements.
Right now, however, you appear to have no way to actuate the shutter, given how far you've pulled it apart (I'm assuming this is a standard leaf shutter arrangement - I have no specific experience with the YK). I would clean the various shutter parts you've removed and reinstall them before trying the graphite treatment (everything under the speed cam plate, plus the plate itself).
Worst case scenario, it doesn't work and you have to disassemble further. As long as you're gentle, there's really nothing to lose by trying.