I would hope it's a MkIII. It should have the chinstrap rivets about 3" up from the rim if it is. The MkIV has them much nearer the edge.
Postwar Mk IV. Yet again. Whoever dressed the manakin needs a slap for making the reenactor/collectorism of shoving both utility pouches on the front. And like not blancoing the core webbing. Then again when the likes of NAM put out post-war kit on display now, who cares for accuracy anymore! [Also where was this taken...]
For some reason museums appear to increasingly care less about accuracy of kit on display. NAM was most recent culprit, now Overloon. Joy!
Yes, not good. Mind you, they do have some credit with me. Few years back in a fashionably PC move the name was changed from 'War & Resistance museum 'to 'Liberty Park'. It is now back to what it is: a War museum.