The chin is ACE, as is all the actual skin (although a bit more chicken-neckage might be in order to tie in with the rendering of the face).
The helmet is a pretty retro-feel to it, of which I'm not a fan (preferring the later versions). It seems to be a pretty tight fit, tucking in at the back which isn't something I've seen much. The shield doesn't seem to be able to hold the respirator behind it, but then that WAS the old-school look. Pretty good I have to say. The dull sheen on the helmet is particularly nicely done.
Good stuff, will you be tweaking and adjusting it to any major degree?