The 1st Battalion West Surrey was stationed in Malta in 1892 and it appears that this type of helmet was not uncommon in Mediterranean stations for the British Army. However, the Dress Regulations of 1894 state that puggarees were to be worn in such stations as India, Bermuda, Ceylon, Hong Kong, Egypt, the Straits Settlements, West Indies, Mauritius, Malta, West Coast of Africa and Cyprus and that the full Home Service pattern helmet plate was to be worn at other stations, i.e. those where the puggaree was not authorized. There was a term “Mediterranean Order” which translated to no puggaree but full helmet plate and it appears that the cork ventilation was also a feature of this “order.” In 1899 puggarees were authorised for all stations abroad.
Also of note is the use of external chinchain bosses (rosettes) which was not unusual but not authorized. It seems, once again, that almost anything “goes” in the British Army of that time.
The real reason for four panel helmets will probably never be known as the Army Order 35 of 1877 stipulated six panels and was never overridden. It would have been cheaper for helmet makers to make them in six panels because of far less wastage of finishing cloth.
It seems that some regiments in the late Victorian and early Edwardian times bought their men a second helmet from regimental funds. Generally, this was a smart white helmet only worn on parades and they were often finished to a higher quality than the government Pimlico issued examples. It should be mentioned that khaki versions are frequently found.
The four panel version of the helmet was used in British colonies and above is an example from Queensland, Australia. Below is a Canadian example.
Thanks go to Christopher Mills (The Jaunty Hat) who generously provided valuable information.