Rolex ref 1625 Thunderbird

This is a Rolex 1625 Thunderbird from 4th quarter 1965. The 1625 model in my opinion is the undervalued watch when compared with the Rolex 1601 Datejust. It has a rotating bezel versus a fixed bezel from the 1601. It is a good hybrid between the dress watch and the Rolex sports model

Muammar Gaddafi took over Libya in 1969 in a coup when he was only 27 years old. He ruled Libya for 42 years. We see Muammar Gaddafi in the photo below from 1971 wearing his Rolex Datejust Thunderbird 1625

Turn-O-Graph timeline from the forum

1952-1953: Ref. 6202 debuts, the first Turn-O-Graph. While the steel model resembles the soon-to-be-released Submariner, the two-tone model has a gold bezel that most associate with the later "Thunderbird" models. A few 6202's are named "Monometer."

1953-1956: Ref. 6309 ditches the Sub-style bezel in favor of the gold "Thunderbird" one. Full gold is now an option, as is a left-hand crown.

1956-1959: Ref. 6609 is "basically the same as 6309 but with updated 1065 movement (based on the cal. 1030 but with date)" This is the model that sparked the nickname "Thunderbird" because Rolex famously gifted some to the USAF Thunderbirds.

1957: Ref. 6602, a rare Datejust model called the "Transcontinental," is the only Rolex ever made with a 12-hour rotating bezel.

1959-1976: Ref. 1625 gets a movement upgrade to the Caliber 1500 series. At first it sports a 1565 movement, with 26 jewels vibrating at 5 beats per second. Starting in 1965, the 25-jewel 1575 movement ups the rate to 5.5 beats per second while increasing the power reserve from 42 to 48 hours. The Rolex 1625 is slightly smaller than the 1601 Datejust and the dial is also very slightly smaller and is not interchangeable. 

1977-1987: Ref. 16250/16253/16258 gets a movement upgrade to Caliber 3035, now vibrating at 8 beats per second like modern Rolexes do.

1988 - 2003: Ref. 16263/16264 gets upgraded to a sapphire crystal and Caliber 3135 movement. No more in solid gold.