British army trucks of the 30s: identification

[Konstantin Chernov]

1. Two months after the start of World War II, an exhibition of Leyland military equipment was opened. From left to right: Lynx Truck, M.A.P. 11 - Beaver-EEL Airfield Defense Vehicle (WLW5), L1710344 - Retriever Breakdown (WLW4), and L1712679 - Retriever 6-Wheel GS Truck (WLW1).
2. The 1968 Vanderveen Handbook lists eight variations of the Retriever model.
3. One of them is the WLW3.
In total, there are four modifications. I couldn't find any data on the others.
WLW1 - GS
WLW1C - ?
WLW2A - ?
WLW3 - searchlight
WLW3A - ?
WLW4 - breakdown
WLW4A - ?
WLW4B - ?
WLW5 - armored vehicle for airfield defense