I think Chris is right, the cost involved works against those 3.
They are true variations in my mind, with front and back differences. They were not intentional or corrected errors, but did the result from the decision to double print them with resulting differences
And the differences are no less distinctive than the 58 Herer or 57 Bakep or the 52 Campos Black Star, or 61 Fairly green smudge, Brian, all of which PSA has recognized. You mentioned Campanella. There is a recurring print defect on some of his cards, as well as several others in that set ( Snider is another). But the Mantle, Thompson and Robinson differences are not print defects.
I am not a registry guy, just a set collector. I think SCD did list them, so I had to have them
