C60L tanker truck

[Grant Bowker]

Although this isn't a 100% guaranteed answer, I believe this can reasonably be taken as a 800 gallon petrol tanker with 5K1 body.
Your photo looks similar to that of the 3 ton Gasoline Tank found in the Observer's Fighting Vehicle Directory, World War 2 (1969 edition). It also looks like the 3 ton Bulk Petrol Lorry pictured in Canada's Fighting Vehicles Vol 1. (2nd ed.)
The statement of 5K1 body is based on the SBMA maintenance and parts manual (SB-11) for 800 gallon petrol tankers which shows all except the 5K1 body having a plain tank, without the pump and hose compartment at the rear that the 5K1 has. As a result, the tank on later models is placed further back on the frame. The tool boxes on the left side of the pictured 5K1 body in SB-11 are arranged a little differently but appear to be the same boxes.


The sources listed above didn't give any detail on a water tanker but the AEDB Design Record (vol. 6) does list 200, 350 and 450 gal water tankers (in addition to the 180 gal trailer). It makes sense that the water tanks should be smaller due to the greater specific gravity of water (1.0) compared to petrol (approx 0.75) to avoid overloading the chassis.