"After the Battle" magazine issue 87 contains an article about the making of "The Wooden Horse" As Well as "The Great Escape". It states that for "The Wooden Horse" a replica of Stalag Luft 3 was built on Luneburg Heath in Germany near the town of Soltau "Built and finished entirely with German Labour, the project provided a temporary boost to the local economy" Filming began in Autumn 1949. Officers and guards of the camp were played by ex-members of the Wermacht. The article also states that the rest of the film was filmed in denmark and Shepperton Studios. Principal street scenes were filmed in Lubeck. Hope this helps!