Grosset & Dunlap purple/white spine formats

I'll admit, in this section, I'm lumping a few formats into one.  James Keeline (correctly) separates these picture cover formats out into different formats / variations.  There were variations, as James shows on his page (listed under Further Resources). 

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Although all titles still in print in the '70s were eventually available with this purple/white spine, the earliest printings of #71 and #72 were not printed in this format (until the mid-'80s)--originally they were published with solid purple spines, as seen on the Solid-Purple-Spine page.

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Variations of the rear covers in this picture-cover format, with the earliest to the left:

1st format picture-cover rear cover

Glossy cover stock. Probably the last format to be printed.

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James Keeline provided this list he created regarding these printings (which ones were printed in this format, and other characteristics about them):

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There is also an oddity that I just came across--I don't know how widespread it is:  This is a copy of Sun Moon Cruise (#68) without the number on the spine OR the front cover. 

Below IN the full list is a picture of another partially similar oddity: #67 without a number on the front cover as well.

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Any blank spots below are simply because I don't have the book in my collection.  If it has a spot below, it *does* exist. 

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#1

#6

#11

#16

#24

#43

#48

#53

#58

#63

#67 WITH # on cover

#72

#2

#7

#12

#17

#25

#44

#49

#54

#59

#64

#68

#3

#8

#13

#18

#27

#45

#50

#55

#60

#65

#69

#4

#9

#14

#19

#38

#46

#51

#56

#61

#66

#70

#5

#10

#15

#20

#42

#47

#52

#57

#62

#67 WITHOUT # on cover

#71