I also belong to a WWII collectors forum, and there's this one guy... okay all of them, and they will literally scrutinize a helmet 'til their eyes bleed and give a full report on what it rates as. They're not "wannabe keyboard experts", as all of their opinions match up perfectly. One of them has been doing it for 30 years, and even has a very helpful website devoted to helmets. The general consensus is that the white paint is fake, and for two very important reasons.
German Helmets were never manufactured in camouflaged colors. The paints colors used by helmet manufacturers were Feldgrau, Apple green, pea green and Luftwaffe Blue. When a soldier wanted to camouflage his helmet, he'd have to do it himself. The subject of German camo helmets is very interesting, and not boring at all really.
Anyways, winter camo was applied two ways. Whitewash was by far the most common winter camo used, and it could be washed off in the spring. White paint was rarely used, and when it was, it would have to be painted around the decal, not over it. Clearly this helmet had it's decal painted over, not something that would have been done. I think the most important part however, is the fact that the general consensus is that it is postwar paint applied by a greedy, but stupid faker. Nothing that is not fixable however.
It's funny, the purists got all mad at me because I had bought the helmet without consulting anyone first, a big no-no. One even went so far as to say that I'd regret it, because it was probably a fake. O' ye of little faith, I did quite well actually.