The car Harry is driving at the beginning of the film is a 1965 Bently S3 Continental two-door saloon by James Young. One of only two made.
This was not the only time Günter Meisner portrayed Adolf Hitler. He also assumed that role in The Winds of War (1983), Winston Churchill: The Wilderness Years (1981), and Ace of Aces (1982). However, he is probably best remembered as Mr. Slugworth in Willy Wonka & the Chocolate Factory (1971).
At about $140 per ounce for gold at the time, the $6M worth would have weighed nearly 1 1/2 tons.
Aired on NBC in the United States on 31 December 1979, under the alternate title "Hitler's Gold."
Holtz is depicted as being a Reichsleiter in the Nazi Party - the top political rank second only to Hitler. He is dressed up in the light brown mustard colored uniform with the appropriate collar tabs and armband. However, these appear to be poorly made, but they are just reproductions from a theatrical costume company thirty years after the war. Holtz is a fictional character, but with him still being in prison so long after the war, he could be analogous to Rudolf Hess, former deputy to Hitler who was still serving his life sentence in Spandau Prison in West Berlin at the time this picture was made. He would continue as such until his suicide in 1987, age 93.