The series was issued in two groups 1-40 and 41-100.  
 
There are groups of ten of the same woman in different poses for the first 40 cards
  1-10 is Pitonof, 11-20 Miss Ideal, 21-30 Odiva, 31-40 Annette Kellermann.  
 
Numerous women are portrayed in the second group, 41 -100, 
many with more than one card (different poses). 
 
The first group is more common than the second.
 
I have seen a number of the first group (1-40) with more than one back, 
though #7 is confirmed with two different backs (different wording). 
I don't recall seeing any of the second group with two backs but haven't 
studied the series closely enough to say for sure one way or another.