I don't know much about engraving but it seems that the artist's style should be fairly distinctive so perhaps he can be found?
What is the white metal would you guess? Platinum?
This is the third rifle that I have seen with Pleistocene scenes. And I like it a lot. I have Pleistocene cave paintings engraved on my highwall because - well because I like them more than realistic scenes, but this gun has something that definitely reaches me.
I found a possible book source for the phrasing from Michael's discovery but my web browser tells me that it is likely infected with a virus of some sort. My own university library does not appear to have the book "Extinct Species Of The World". Maybe someone else has a possible source.
Those words seem to have been plagarized hundreds of times w/o citing the author though. However, I really want to know about the rifle (and its maker and original owner), so I posted a note on the Marlinowners.com collectors' forum. Probably a long shot but I'm not so resourceful as Michael.