Thanks Walker
As for Portfolio Rag, I do not see it that “black” 
I still think, that it has the nicest touch and a very nice structure - also in the coating which means in terms of detail sharpness.
But anyhow: I have printed the calibration target and get a Dmax of 1.58 at 65/70 %.
This is what I also get when linearizing from PhotoRag quads. The Innova IFA 11 remains at 1.56.
So, for the moment I think that I can get out the most of what is in my inks - and the next step would be to install a fresh inkset.
Best, Markus