Woodbridge Antiques has dated this piece to the 1930s.
The silver maker's mark is also visible for the renowned silversmith: Joseph Gloster Ltd. There is also a capacity mark: 1 Gill and partial hallmarks under the lid.

A super item, fabulous as a gift for any occasion, coming of age, retirement, new baby!
Condition: This flask is in super condition.
Measurements: Height: (From base to top of lid): 11.3 cm Width: 7 cm Depth: 2 cm
Weight: 139.6 grams (heavy gauge).
Weights and measurements are approximate.
NJL36346
Woodbridge Antiques has dated this piece to the 1930s.
Specialists in quality antique silver, fine jewellery & accessories
You can view the stock and full dealer information on the Woodbridge Antiques Profile Page