This is the 3rd official G&D dust jacket format
Although very similiar to the 2nd dust jacket format, this one has the red circle on the spine designating the "age range" for the series. #8 pictured below does not appear at first glance to have this red circle, but if you enlarge it you can see it is faded.
Once again, I don't know how many were printed in this format.
Once again, I don't know how many were printed in this format.