To update: I took the CDV to a well respected auctioneer near my house to get a second opinion and he said he doesn't specialize in baseball but he strongly suspects that it's a pirated version not from the original negative (what I suspected). He said that pirated versions usually have blank mounts but not always. It could have either been authorized by Millard himself or perhaps the creation of a rogue employee. I asked him how he would price such an item and he said he's not sure about this particular subject, but that it should be worth significantly less than an original, but it depends on various factors...
Definitely a huge bummer.
