I don't know anything about Mr. Paxton himself, but the knife in the link below has been for sale on the Collector Firearms site for quite a long while. The first time I saw it was in an Amoskeag auction in September 2013 where it sold for $850. It later showed up on eBay for a while without selling and then went to Collector Firearms. I like scrimshawed old yellow micarta but never liked Paxton's bear much.
http://www.collectorsfirearms.com/randall-model-12-big-bear-bowie-k1537/

- -Buckspen