comic_craig,
I guess the sculpt photo didn’t get the right message across. I thought it would. I guess what I should have said was this… Seeing as it has gone this far and is looking so well, I would take it to the next level. Having researched rhinos myself, I am aware that they are varied and differ greatly, but what I would suggest is to review your reference photos, (gather even more of them as well), and then push the tertiary forms and details even further to give it some more character. (I don’t mean in a cartoony fashion)
It is a great model. You could stop where you are, and be pleased, but since you’ve come this far and are asking for suggestions, I say keep going. Push it even further. Surround yourself with as much reference as possible, and find the one that calls to you, and make it so.
I would make some of the wrinkles and cracks a bit deeper as well. Rhinos are a plethora of details, the closer you get to them.
Just my 2 cents, and I gave you five stars by the way.
Cheers,
~BW