I got this picture from a book published in June 1933 so it must be older.
The text says: "Special Carden Loyd Light Tractor". What puzzles me is the gun. It does not look British but more like a Dutch M/1903 Krupp (-Siderius). British type steel helmets. The Dutch had another type and in Belgium they used the French Adrian type.
Number D 25 does not look British either.
So where and what type?