Thanks a lot for your help!!
The good news is that maybe you are right with the shutter, maybe it is a Thornton Pickard Shutter, i donīt know.. it does have 3 rollers, so not very sure.
The bad news, is that the one curtain left, is so dry and cracky that i need to replace this one too. Still looking for some sort of fabric replacement.
I send you a private massage with my email.