Have seen these marks several times on late 19th-early 20th century Hanau-type silver, and from what can be seen of your piece, it would appear to be consistent with Hanau manufacture. Please see this page, with those marks appearing with a mark attributed here to Wolf & Knell:
http://www.925-1000.com/Fgerman_hanau_marks_01.html" onclick="window.open(this.href);return false;
~Cheryl