That is really nice. You captured the face and way-too-big overcoat very well.
My comments would be that the boots look a bit too modern. i'm also not sure about the putees...they look more WW1 than WW2. Although the german wore just about anything in those last war days so it could well be correct.
I'd be interested to have a copy if you'd go for it.
Cheers,
Adrian