S/M 2031 mystery

[David_Hayward (RIP)]

I have a Xerox of an official photo of a #12 Cab 15-cwt G/S 4 x 2 CMP, and it is labelled as [British contract] 'S/M 2031'. The description on the negative says that is is a Ford 4 x 2 i.e. F15 BUT the onyl evidence I have from the Census Book is of two C15s. The front bumper guard APPEARS to be a Ford one, although it is not conclusive. Somewhere I have trawled up evidence that S/M 2031 was for F15s. It does seem odd that ther were just two C15s under this contract but a heck of a lot of sense if S/M 2031 was for Mid-East or Far East [Singapore] or African delivery in which case they had local WD Census Numbers allocated.

Anyone got any evidence of S/M 2031 please?