The specifications you provided correspond to a highly sought-after, elite mid-century timepiece: the 1960s Vacheron Constantin Calatrava (Reference 6562) in Stainless Steel.

  Vintage stainless steel dress watches from Vacheron Constantin are incredibly rare, as the historic Geneva manufacture primarily produced their timepieces in precious metals like gold or platinum during this era.

• Case Diameter: 35mm, which represents a distinct, larger architectural presence relative to traditional 1960s dress watches. 

• Case Material: Stainless steel with a robust screw-down case back—a rare and highly collectible combination for vintage Vacheron models. 

• Dial: Beautifully minimalist satine/sunburst silver dial, typically detailed with applied faceted baton hour markers and classic dauphine or baton hands. 

• Complication: Features a clean date aperture located at 3 o'clock (though a sister variant without a date complication was also produced).