Looking good Peter. I like the leather, and the finish of the helmet.
Whilst I agree somewhat with Martin (I would have gone for a green, or faded green), the variety of colour(shades) as issued, combined with the very destructive environmental conditions, make arguing about the "correct" colour a bit superfluous. The execution of your chosen scheme is great.
Edit:
Having just read the rest of the post (I should refresh the page before replying...
),
I would add that using WWII photographs is tricky, and should not be used as 'absolute truth' that this never happened, or that always happened. The German Army Command changed their orders regarding the wear of headgear, unit insignia, rank insignia, general uniform issue etc very often, and the troops in the field should as often ignore these orders,..
Leather webbing may not heve been routinely issued, but that does not mean that veterans, or replacement troops, didnt bring their own.