Upper right corner:
http://books.google.com/books?id=kagMAAAAIAAJ&pg=PA135
Other maps:
http://www.ostpreussen.net/index.php?seite_id=12&kreis=34
http://upload.wikimedia.org/wikipedia/commons/thumb/d/d9/KALININGRAD_FINAL.svg/800px-KALININGRAD_FINAL.svg.png
http://www.kronoskaf.com/syw/images/thumb/6/67/1757_Battle_of_Gross-J%C3%A4gersdorf.jpg/616px-1757_Battle_of_Gross-J%C3%A4gersdorf.jpg