Ok...
Conversion is good. Black is black and the skin is not blown.
The contrast of the range is pleasing for my eye, though maybe try and squeeze some more detail from the lighter side of the face. I can see from the EXIF you are in really close. Brave man. I was going to say its got a little movement to it but with a shutter speed of 1/15th its bloody good going mate, really good. I have to rely on image stabilisers but then again i'm an insomniac beer lover with a history of not looking after himself. hats off to you for that.
Improvements? For my taste...maybe improve crop...something not feeling right about it...and a teeney bit more detail.

other than that its all good buddy...shame you never got a release., real shame. apologies for typing. trying to type with 18 month old on my lap who wants to press every key!