I have had this a while and shown it before but I have been given some conflicting information on it's date and had thought it was probably 1920's-30's and was for an officer of the S. Lancashire regiment. It is a private purchase version made by Hawkes & Co of London.
Following an update from a very well known collector of Wolseley helmets, Stuart Bates, it has now been identified as having a liner fixing design which was patented in 1916/17, Hawkes patent 103425 of 1916/17 and would date to the middle of WWI and as mentioned above would have been for the South Lancashire regiment and was probably part of the 1st battalion, though might have been in one of the TA or War service battalions.
The S. Lancs in the First World War, 1914–1918
The 1st Battalion spent the war on garrison duty in Quetta, Baluchistan, on the North-West Frontier. The 2nd Battalion spent the entire war on the Western Front. The 3rd (Reserve) Battalion was a depot and training battalion stationed in Lancashire thoroughout the war. The Territorial and war-service battalions fought on the Western Front, in Mesopotamia, Gallipoli and Macedonia.