Two random observations, for what they are worth.
The photos of the Coastguardsmen are from footage taken at Normandy, evacuating casualties. The "V" and the other swabs of paint seen on the top and rear of their helmets is vesicant detection paint, applied specifically for the invasion.
I don't know how long you have been collecting, but when I started, back in the early 1980s, you could walk into almost any Army/Navy surplus store and buy a pre-packaged square of camouflage netting and scrim. Enough to do about two helmets. It was packaged in a clear plastic bag with a cardboard top to hang from a peg in the store. I don't recall who packaged them, but it was someone like Rothco, or one of the other big distributors. The full sized vehicle nets were also readily available. That was 35, not 75 years ago, but you would expect the burlap scrim to deteriorate a bit even over that time span. Something to consider before you decide you have an untouched Ranger helmet from Anzio.
Circa 1989, some of that same scrim I attached to a British-made net for a mannequin in my long-defunct war room:
Edited by pararaftanr2, 03 August 2018 - 11:24 AM.