Useful points about the Vickers. There is a pdf of the Vickers .303 MkIV MG (1930) manual on the internet with excellent line drawings which show the points you make. The steam tube is much finer and connects at the bottom of the jacket*.
The scope on the SMLE should be about a third of the length of the rifle barrel, breech etc and doesn't go much beyond the rear of the bolt. Either the rifle is small or the scope large or a bit of both. Not sure why the group doesn't have a Bren.
Nice to see rolled up sleeves makes them useful to fight the Japanese or in Italy, Greece etc.
*water goes in by a funnel in the plug at the top of the jacket just in front of the breech