I've been using a Konica III refurbished by Greg Weber about 10 years ago. The shutter has become sluggish, slow to open at least for the first few actuations, so needs a CLA. Can anyone recommend someone who can do this? Unfortunately, Greg Weber is no longer doing repairs, or at least not now.
Oil has probably crept back onto the shutter blades. It's a common problem.
You can partially clean the blades yourself by unscrewing the front group of the lens (unscrew the filter ring), exposing the blades. Then gently wipe the shutter blades with a cotton bud soaked with naphtha (such as Ronsonol). Fire and re-wipe a few times. This cleaning should last for at least a day, letting you shoot an event.
BTW, the lens on this camera is excellent in my experience.