Great stuff, Leon -- thanks for scanning and posting!
Also interesting to note that even as early as 1973, hobbyists were clamoring for the days when collecting cards was done for fun and not as an investment.
"A mint card is a mint card regardless of age!! It is not the condition of the card that should be lowered, but the condition in which you will accept the card that should be lowered." -- Lionel Carter
Looks like Mr. Carter was willing to go down to "EX-MT" condition on his E cards...
(note: not my cards. Images were saved years ago when Carter's collection was sold after his passing. Shown here as a testament to his eye for condition)