Francie and Casey single doll case is rare

I have a new doll case to write about.  I can't believe that it was back in 2015 that I did all those "case studies" (for want of a better term!).

My newest acquisition is the 1968 Francie and Casey single doll case.  It's dated 1967 and shows a blonde Twist N Turn Francie in 1207 Floating In and a brunette Twist N Turn Casey in 1215 The Combo, both from 1968.

I don't own The Combo but I do own Floating In.  Note that the picture on the case has the diagonal in the opposite direction as the actual dress.  If you recall, I noticed that a lot of the clothing shown on the cases are flips of what the outfits really looked like.

I looked up this case in several locations, but it showed up only once on etsy.  I am assuming it is rare.

I figure that the Francie on the case is probably cold
or that the Casey on the case is sweating to death,
because their outfits are for opposite seasons.