Last German kaiser's heirs fight for riches lost behind Iron Curtain With its half-timbering, its Tudor-style architecture and its six interior courtyards, the Cecilienhof Castle in Potsdam near Berlin is in the middle of a fierce battle between the German authorities and the family of the country's last Emperor, William II. Relegated to the history books until now, the Hohenzollerns are resurging to claim property confiscated by the Soviets in 1945, including famous castles and thousands of pieces of art. IMAGES AND SOUNDBITES of an historian and of the Hohenzollerns' lawyer