Bussy, perhaps you were thinking of the similar statue of William I at the Deutches Eck in Koblenz? It was wrecked during WW II, The plinth was left as a monument to German unity throughout the cold war. A new statue of the same design was finally added after German re-unification. My wife and I used to live in Simmern. We were close to Koblenz and used to go there often. Great model shops and the Wehrtechniche Museum which had a great military history book and model shop attached to it.
Cheers,
Glen