Good point; see below.

If that does not work, go to the site of the Digital Repository of Scientific Institutes where there search is at:

http://bibliotekacyfrowa.pan.pl/dlibra?action=ChangeLanguageAction&language=en

and search for the title:

Karte von Ost-Preussen nebst Preussisch Litthauen und West-Preussen nebst dem Netzdistrict

Enjoy. - R