Here is a Omega Seamaster Automatic Calendar watch. This automatic calendar watch is the third generation of the "Seamaster Calendar" model, and it is the first Omega Seamaster model to carry a calendar disc for the 3 o'clock position. The 20 jewels movement is an Omega caliber 503 with a swan neck regulator. It has been fully serviced and running accurately. The movement serial number is 16212200, dating this watch to 1958. Uncommon luminousless original dial in well-aged condition. Original signed crown. Crystal is brand new—brand new 18mm matching high-quality genuine leather strap. The solid stainless steel original case measures 34mm, excluding the crown by 42.3mm lug tip to lug tip. Case model 2849-8 SC. The calendar feature is working accurately. The wrist size in the photo is 6 inches.
1958 OMEGA SEAMASTER CALENDAR
Circa: 1958
Model: Seamaster
Caliber: 503
Movement serial #: 16212200
Jewel count: 20 jewels
Movement Type: automatic wind
Case model: 2849-8 SC
Case material: Solid stainless steel
Case gasket: O-Ring rubber gasket
Crystal: Acrylic New crystal
Crown: Signed
Case Diameter excluding crown: 34mm
Case length lug tip to lug tip: 42.3mm
Dial: Factory original finish
Hand type: Dauphine (original)
Strap material: genuine leather
Strap width between lugs: 18mm
Wrist size in photo: 6 inches