Update: I submitted two of the "blank-backs" (Boris Martin and Jeff Heath) along with my regular order of 19 different T205 cards to SGC, and my order was accepted on 9/10. Just a few minutes ago I got an email from SGC advising me that my return order had shipped, and the grading results were available for viewing.
Both "blank-back" 1949 Bowmans received the grade
ALTERED
I'm not exactly sure what this means, but I assume it's not good
And I also assume the cards were not slabbed?
Larry