I just wonder how many of these plates are fake though. The reason I say this is, I used to make plaques for wholesale to the local card shops. I had a guy who made my nameplates for me. And he could buy all kinds of the metals, just like what those plates are, and print photos onto them. With photoshop, you could make them in magenta, yellow, black, and such.
I have seen guys walking around at shows, back in the day (like 10 years ago) before plates were cool, and selling metal "printing plates" of historical event newspapers. But they also had some printed up with multiple articles of certain players on one sheet, poster size. And they had multiples of each.
The only thing that saves these printing plates today are those stickers, and we all know how those have been faked, and/or peeled from one and transferred to another. I was trying to locate the seller on ebay, as there is one from Tiawan, who has been listing a ton of printing plates, all 1/1s naturally, but says they don't have any stickers or such. Most he said came from Fleer bankruptcy, which I don't believe Fleer used stickers. But he had tons and tons of them, all big name stars. And had others that weren't Fleer.
I can say I have only pulled one, and that thing was a clean as a whistle. It actually made me think back to the days of my engraver, and how simple it was for him to print. It looked perfect, as if it was never used for anything. Just printed onto the metal stock, cut out, and placed into a pack for us to find.