Older pictures, but this one. My 1933 Rolex Prince Observatory duo-dial. The only one of these I have ever run into with 18-jewels (15 and17, typically), and adjusted to 6 positions. Gruen used this movement as well. Suspect it was made by Aegler, for Rolex. I am the second owner. My late father having bought this one in Saskatoon, Saskatchewan. Unfortunately, a gold filled case.
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