Hallo,
Finnaly had the time to show the watermark from the cover on post 12.
Identifiable? or just generic?
Filigrana will like it I think 
Edit: Erdinger, your previous post is a charm. I read on different platforms the problem with the way papers are made since the 1800. Specially the white papers which are not normal in natural way and are made chimically white.
Very good post! and nice piece there!
Best regards
Sylvain