Received several emails about the Lum Wharncliff currently on Ebay. And the answers are:
1) Bob would have called it a Deluxe (SS Bolster) Stag Wharncliff/Caper.
2) It's most likely a one-off. Either customer order, or just something Bob made because he wanted to.
3) The price is more than fair given the condition of the knife. But collectors would probably have an issue with that deep gash on the spine.
4) The sheath looks like a Lum original. Bob has been known to stamp decorate his sheaths. Not often, but they do exist. A quick email to the seller for a picture of the backside would confirm this.
Good luck to all the bidders.
Update on 12/06/13: Still there and price dropped to $695.
Update on 12/18/13: Knife didn't sell, and was relisted. It was sold via an undisclosed Best Offer. Congrats to the new owner.