Rob Miller pointed out in an earlier thread that this appears to be one of the 18" wheeled RAF contract machines and these do not strictly follow the changes that we see in WD (army) contracts.
The fuel tank, steel footrests and WD rear light all point to a post-1942 date. The RAF didn't generally specify the fitting of panniers which means that the earlier type of rear carrier continued to be fitted and the bike in general doesn't look to be new and ex-factory.
I don't believe that there is any real evidence to show that the British or Commonwealth Armies ordered any quantities of passenger sidecar machines, ignoring the Big 4 and oddities like the re-directed US stuff.
