Here is an all-original and rare transitional-model 39mm 1981 Rolex Oyster Perpetual GMT-Master. This is the ref. 16750, which replaced the 1675 and was only produced for two years. The caliber 3075 automatic winding movement was introduced with this model and only used for two years. The 3075 offered 28,800 bph rate as compared to 19,800 for the previous caliber 1575. The glossy dial is really quite pretty, having deeply aged markers and matching original hands. These watches were serviced by Rolex and often the matte dials were changed to the raised white-gold-surrounded glossy dial such as this. The movement was cleaned and is accurate. The steel case is very clean with no dings or major scratches. The 78360 bracelet is very clean.