The 4 door cab was only for the Fireengine, as far i remember correctly. So it looked:
There was also a red version in military use. Was funny during an exercise drill, when our helicopter operated from a dispersal airfield somewhere in the bush. All was perfectly camoflaged, nothing was to seen from flying helicopter. Only a bright red fire engine stand in the mid of nowhere.
A distinguishing feature between military and civil W50 was the round command hatch for the co-driver. Big tires are not a sure distinguishing feature. This had had W50 for agricultural use too.