I still see no evidence presented here that Camo'd Helmets were done in theatre as a common occurance with US Army (in fact nothing here shows they did it at all during the war, although I think that is subject to debate).
The fact that the photos from the album shows unit insignias screems postwar.
I could not find a 99th Engineers in any Div. on the internet, that does not mean they weren'e Army or Corps assets. What's frustrating is I have a complete set of the US Army Official records boxed up at the moment.
If you can identify the unit patch and when wear started you might have an arguement for the album photos. IIRC there si only one Wartime documented use of Insignia from a Div (81st?). mostly all being 1919 additions. That could place the photos in France or Germany but still not wartime.
It is as incorrect to say that there were no American camouflaged helmets used during WW1, as it is to say there were many.
Captain Dunn's painting of the American Machine Gunner wearing the painted camouflaged helmet, indicates that they did exist during WW1, Tom W's photographs show that they did exist, Dave G an American Collector for some 40 years acknowleges that they existed, albeit in very small numbers.
The problem we have, is that due to their rarity, actual photographs with documented dates and locations are also rare. My experience is that photographs are published in various formats, and Tom W's photograph of the Americans celebrating the Armistice could be the proof positive. In the photograph he has, he can clearly see the American camouflaged helmets for himself, and we must respect that. Unfortunately, when he posts the photograph, it does not reproduce as clearly. There is a good chance that particular photograph is somewhere else in another publication, or on some website, and then, what Tom W can see, we shall all see.
It is only a matter of time, before someone posts other documented photographs showing the Americans wearing painted camouflaged helmets during WW1.