1965 was a pivotal transition year for the 1803. Earlier models used the Caliber 1555 (18,000 bph), but Rolex upgraded to the higher-beat Caliber 1556 (19,800 bph) around this time, improving shock resistance and precision.

The 1965 1803 was the last reference in the Day-Date range to feature the iconic "Pie-Pan" Dial where the outer edge slopes downward like an inverted pan, creating unique light-play and depth.

The 36mm case is crafted exclusively from precious metals and is topped with the signature fluted bezel.

Unlike modern versions, the 1803 uses a domed acrylic (plexiglass) crystal, which provides a "warm" vintage glow and sits higher on the case.

The watch movement is a non-quickset model, meaning the user must cycle the hands through 24-hour rotations to change the day and date apertures—a ritual many vintage enthusiasts consider part of its charm. 

While earlier versions featured leaf-shaped hands, the 1803 from the mid-60s featured straight "baton" hands.

This example is in excellent mechanical and cosmetic condition and the gold case and bezel have achieved a beautiful darkening 'blooming' which we have left untouched, however, it could easily be polished back, by hand, to as new should the new owner prefer. 

The watch is provided on an unworn vintage Rolex gloss black crocodile strap with original Rolex vintage gold-plated buckle, and with a genuine Rolex age related box.