Doesn't that definition simply apply to ..

... any soldier in full kit? In that sense it is corroborated by my dad (RAF wartime) who refered to senior officer's in full regalia as "dressed up like an F'in' Christmas Tree - with all the baubles"

For clarification this means "looking like he had scrambled egg thrown at him".

No reference to CMP's there but the inference is transferable.

Authentic or not I suggest like a lot of collector's or re-enactor's 'in' terms they are not clear means of communicating accurate details.

Keith