I don't know of any dug ones. I have seen three or four in the past 12 years or so. I believe two were in the Adamson auction sold through James D Julia that can still be viewed online. There was one with "Excelsior" stamped in it and an unmarked one I believe. This was near the market peak and at Mansfield shortly after, Rick Burton had two (same pair I am guessing) for sale for a crazy big price. Not sure (doubt) he got it but it was in the low five figures each! Heritage Auctions may have had one once too, I cannot remember for sure where I saw the others. In each case they were well North of anything I'd consider paying
