The reason I raised the matter is that the Adrian was extremely rare amongst Russian troops, and I remain to be convinced about the Lewis gun, which appeared late in the War, if at all. That restricts the set's usefulness for The Great War, although it is well suited to the Civil War.
Thank you for the link to the reenactors' site. Extremely interesting. There are a couple of "Finnish" helmets and also two Adrians on show. One assumes that the reenactors have done their research, and the proportion of helmets is very small.