As the WOT6 was a Machinery lorry, it would have been in service with REME, the one I was involved in restoring is shown here, with the Blue, Yellow and Red sign to denote REME and 99 over it for Workshop unit. The other sign was for 6th Guards Armoured Brigade, significant in our area as one of the first V1 flying bombs dropped on their camp and killed a large number of REME personnel.
The QL is mine, photo taken about 14 years ago.