The blue Whitman album and folder was made to hold the bigboy of doubled Wheat ear cents, the 1955-P, and labeled that way. Other manufacturers just add the unlabeled space like yours. What most do, including myself is fill the hole w/ the "Poor man's" doubled-die. That's the die deteriorated version where the date's 5's have a "ghosting" effect, actually just plum worn out die.
