Leica IIf shutter curtains smear

[laptoprob]

Sounds silly, but my IIf continues to suffer from some kind of smearing at the ends of both curtains. The cause is simple: The curtains are of cloth and the uneven thickness of the woven surface causes some black matter to accumulate at the ends of the curtains, where they go around the metal strip inside.
This causes at 1/1000 and 1/500 about 50 pairs of darker and lighter bands as I reported earlier.
Is this a lubrication thing? Should I have to CLA this otherwise perfect little gem? Or is there some remedy to make the shutter slit more even, because that's the only issue there is.

[nikonhswebmaster]

The shutter slit should be clear, if there is crud building up on the ends of the two curtains that is awful. I cannot even imagine what it is other than grease.

The curtains themselves are made of cloth that is rubberized so they are not threads.

When the slit width is set narrow (as in 500 and 1000) you are suggesting that this crud actually bridges the gap and causes odd exposures? Your camera needs to be looked at.

I second the post below, it is very hard to picture the problem, I have never heard of such a thing.

.

[VictorM.]

It's hard to picture the problem, but if the camera needs new curtains and a cla, Oleg K. is good and inexpensive.

http://www.okvintagecamera.com/

[laptoprob]

The curtains don't have a smooth surface. One side does, the rubberized surface. The outside surface that actually goes around the metal shutter 'side' is plain cloth. The two curtains touching each other create the stuff building up.
I will try to clean those surfaces first.