I think the figures in that pic are just mock-ups done for the equipment manual to illustrate the soon to be released Marine combat uni. They look to be 2nd issue soldiers (uni, blue beret and sten gun) with puttees added. The actual Marine combat didn't get a plastic beret until the later designed 'rubber' ones. I think it was common practise for the photographers to use prototypes and kit bashes to represent upcoming sets.
_________________Life moves pretty fast. If you don't stop and look around once in a while, you could miss it.