A little bit more development, I tried out some different styles for facial markings.
The first is a simplified version of realistic wolverine markings, the second is influenced by one of my ink blots. The others are random small changes, the last being a bit too close to the Marvel character's markings. I think I'm happy with the second, as it's simple but also identifiable. Using that along with all my previous reference, I worked up the first complete concept sketch:
This is what I'll post to an online forum I frequent called Colony Of Gamers, to hopefully get as many opinions as possible from my target audience.