This is a 1918 WW1 Sterling Silver Officers Trench Watch, Hallmarked London 1918, the case was made by George Stockwell, who was at the time one of the UKs largest watch case makers. 
 
The case is in very good condition for its age the dial is clear and readable although some of the lumenhas deteriorated with age,
The movement is a Swiss unbranded Jewelled lever movement.   
 
Cosmetically overall this is in very good condition and working well.