I don't do graded cards, so I don't know if the pop reports account for the 60 GRAYback variations in the mid-series (#131-190).
I'm curious if PSA, or SGC, pop reports reflect these extremely rare cards (that I think were actually issued in 1953) ? ?
COLOR variations......
Also, the aforementioned color variations are simply printing errors or printer's variations and I feel that they should not be part of
a "Master Set".
As is obvious when you compare 1st series (1#-80) Black backs vs Red backs, the front colors are somewhat different. The Black
back cards tend to be pale in contrast to the Red backs that are brighter. A trained eye can discern a Black back from a Red back
without flipping the card over.
I have a bunch of these color variations but, I don't include them as part of my master set.
TED Z