One thing- we don't know for a fact that this copy is he missing Mastro copy. It just seems (to me at least) to be the likeliest scenario. Of course, the second most likely scenario is that it's a copy that sold in the 1990s, so that's not a new copy either. But, we really don't know that this is the Mastro copy. As was pointed out, t might just be a promotional image put together with the Mastro scan.
As for fresh-to-market books, if you mean "new to the hobby" then I think we're near the practical end of that possibility. We're looking at a 90-year old original owner for an Action 1 bought at 10 years old. It's still possible, but we're pushing it to the limit these days.
I think (hope?) there will be some surprising collections that come out of early (1st and 2nd generation) fandom.