"Not quite closing fully so as the camera winds", etc. is exactly what I meant when I said "sticking open for the first 1/3 frame or so as the film advances".
As I mentioned, re: the color pix, it could also be that the shutter is fine, but the camera starts winding too soon as the shutter closes.
Also, Excalibur2. This would not affect frame spacing at all.
Nor would this problem cause ghosting in bright light over the entire image. My IIIc has the same problem. After exposure, the curtain does not fully close. The curtain sits there open in front of the last frame you shot until you advance/cock. Thus, the longer you wait after the exposure to advance the film, the worse it is. In bright light, you don't get ghosting at all. You get a jacked up overexposed vertical streak from the shutter hanging up after the exposure, followed by bright horizontal lines from pulling the film across the partly open curtain as you advance and reset the shutter. The camera is unusable in the day because of this.
As for the OP, perhaps the curtain stays open entirely sometimes until the film winds and cocks it. This would drag the whole composition across what you had just exposed, making the ghost effect, the soft effect, and the streak effect.