I know British Mk2 helmets were used well into the 1950's, & some were refurbished.
The two types I know of are either painted dark brown textured paint, or a similar colour & texture to the early war khaki green painted army Mk2's.
The latter green type is not as textured as the wartime ones & normally has an ink stamp on the inside shell which is normally painted smooth matt, & most if not all have post war dated liners.
These ones are quite easy to tell from WW2 issue Mk2's, the dark brown painted ones are a bit of a bugger to tell the difference. Unless it's been refurbished on the early war Mk2's dated before 1939 with the larger Mk2 chin strap lugs as all of these would have been painted khaki green.
The later Mk2's from about 1941/42 would have been factory finish in dark brown, but post war refurbished ones seem to have a white sort of chalky look to them, & post war liners.
Today I came across an Canadian Mk2 with the same refurb as the British ones & it has this same ink stamp inside.
Any idea's anyone.