I think it's looking like a really good start, the front is lovely.

The gems are especially awesome, and the crimson is a great choice.
I'm not sure about the placement of some of the highlight on the back. The 6PM to 4PM section of his lower coat, the bands seem a bit too wide, and actually go back into the recesses in some parts.
I'd recommend shining a hard light down at him, and photographing him like you've done there then keeping that picture to hand and rearranging some of the highlighting.