Outstanding Patek Philippe steel “Jumbo” Nautilus ref. 3700 retailed by Gubelin. Never polished case. Blu-gray Dial with horizontal stripes, featuring Gubelin. Patek Philippe Nautilus clasp. Dim: 42 x 44 mm. Manufactured in 1970’s.
You can read more about the history of this extraordinary reference at “The Onlyvintage Magazine”