The military model was the MAF, a variant of the 350cc MAC. This photo looks like the 500cc MSS with the larger oil tank. It is not a cammy velo, see the breather outlet on the timing cover.
Ian I don't understand your comment about SV? I'll probably get the joke after it's too late to edit
Peter you're right about the timing cover for an MSS (The map of Africa) They often have that lump cast in even though they're not always drilled and tapped for the breather. The other main ID for the KSS and MSS models is the distinctively vertical saddle tube.
I have both military model Velo's MDD and MAF both of which are based on the MAC. Ron