Lecoultre master mariner automatic
35mm x 35mm
13.25mm depth
40mm lug to lug
 
The watch dates to the early 1950s. 
 
The Calibre 476 was the first automatic movement from Jaeger-LeCoultre.
Introduced in 1946, the Calibre 476 came 20 years after John Harwood and Blancpain presented the first automatic wristwatch and 15 years after the Rolex "Perpetual" went into production. It was a bumper movement, not a 360º rotor as in today's watches, but it boasted a respectable 40 hour power reserve and was accurate enough to be certified a chronometer in later years. It ran at 18,000 vph.
The 476 was the basis for the 1948 JLC 481, the first from the company with a power reserve indicator.
 
The case is in good condition with small marks / dints on the case as would be expected for this age. The gold fill has not worn through in any area. It is 14k GF.

The Plexiglas crystal is excellent with some marks visible under close inspection
Dial has blemishes / Patina as can be seen in the pictures, but this is consistent with age and probably slightly better than the average dials ageing. 

The strap is a new genuine leather strap.

The case back, movement and dial all signed Lecoultre. Crown has a mark but it is hard to make out.

The Movement is the superb Jaeger Lecoultre Calibre 476 Automatic Bumper. A serviced movement, working perfectly.