If I could offer a suggestion
This is as close to right as I have ever seen so far, but I think your just a little off the mark because the eyes don't show any sign of his domino mask. Thats a big part of the mask in this artwork, and in a few others.
Other than that and a little fine tune of the mouth, having the scull lines run all the way back behind the head like they did in Batman RED HOOD would allow for the helmet to open in the back like iron man for easy in and out... you got it!!
Here's a quick version of what I mean. Changing the shape makes him meaner in expression also.