Thanks CaptnAL and Riptide.
The "disintegrate" I mentioned is some gunk (black and sticky) that is on the face of the blind and of course, every time we roll it up/down, it sticks to whatever material is already rolled. I would have guessed Veggie or olive oil, but does not smell or is rancid... It just LOOKS to me that something must have spilled on the shelf above and eventually made it "into" the roll of material.
It sticks so bad that it is very hard to roll it down every time... and the fact that it sticks to itself every time...is starting to wear the shade material to the point it has some tiny holes that show when the sun is out...
Perhaps, and only perhaps... if I take it apart, I might stand a chance to clean it right up, as you just mentioned...
I was just thinking that it might be due to change the material... and since I have not been able to find the original that was used... I might have to do all 3 (sliding door, above "cool box" and behind driver (above table).
I did come across an outfit in Germany that has the right material, but of course, not the right colour. Mine is an original James Cook (1997) imported from Germany and mostly blue/grey. The material I saw is beige (sand) and seems to be the match for the North America version. There was a number of changes when they re-designed to become the Airstream.
Here's the link I came up with through the James Cook Forum:
https://www.campingplus.de/campingartikel/remis-springrollo-remisun-creme-127-x-60-cm
If the link does not do it, go to the website:
campingplus.de
There is a reference above about the WESTY MANUAL PDF, that covers the repair.
I am no wizard at searching forums so I wonder if anyone can quickly narrow down where to go... fo me.
Thank to all for sharing info!