According to the German Wikipedia the location was at the Unser Lieben Frauen Kirchhof before the city hall. The equestrian statue was dismantled in May 1942 and the metal donated (I guess to the war) on 6 June 1942. The base was removed after the war. After the war der Kaiser lived in exile in the Netherlands in Doorn (13 miles south of Amersfoort).
Rob thanks for this, I spent a while yesterday looking round the google map for this by the Rathaus in present day Bremen, no wonder I couldn't find it! That also explains that when looking for it, one only finds images on old postcards and not photos from 'today'.I didn't know where the Kaiser WII went after the war, I've been reading the 'new' bio of Edward VII by Jane Ridley and have just read the chapter mentioning Wilhelm II in there.