This would be an Edwardian tattoo or theatrical piece rather than military issue.
The front of the cap features the Argyll and Sutherland Highlanders regimental badge.
Above this is a white pommel and it has a crimson silk liner.
~ Argyll and Sutherland Highlanders ~
The Argyll and Sutherland Highlanders (Princess Louise’s) was an infantry regiment of the British Army until amalgamation into The Royal Regiment of Scotland in 2006.
The regiment was created in 1881 as an amalgamation of the 91st and 93rd Regiments of Foot. The Argyll and Sutherland Highlanders was expanded to 15 battalions during the First World War and nine during the Second World War. The regiment sent an active battalion to serve in the Commonwealth Division in Korea and gained a high public profile for its role in Aden during 1967.
~ Dimensions ~
The hat, from front to back, is 10 inches (25.5cm) long. It has a width of 8 inches (20.5cm) and a height of 7.5 inches (19cm). It weighs 270g.
~ Condition ~
The hat is in fair condition, with some five moth holes to the material. The border towards the lower edge is loose at a point.