I
recently wrote of a Dana Girls picture cover with blue ink on the top edge of the text block. The Dana Girls picture covers normally have green ink on the top of the text block. The book was a probable first printing of
The Mystery of the Stone Tiger.
I just found another Dana Girls picture cover with blue ink on the top edge of the text block.

The ink is partially faded, but it is definitely blue instead of green. This book is an early picture cover printing. It lists to Sierra Gold on the back cover and lists Nancy Drew to Moonstone Castle and Dana Girls to Lost Lake on the inside.
I am curious as to whether anyone else has any Dana Girls picture covers with blue ink on the top page edges. Since we do not have a Dana Girls guide, we have far less knowledge of these types of variations than we do for the Nancy Drew series.
The same rules that apply to the Nancy Drew series also apply to the other Grosset and Dunlap series, and people who collect and sell series books tend to overlook that fact. I often see collectors classify Dana Girls picture covers that list to Stone Tiger on the back cover as first picture cover editions. Unless the book is Stone Tiger, then one listing to Stone Tiger is not a first PC.
The Sierra Gold Mystery was the last Dana Girls book printed with a dust jacket, just as
The Mystery of the Fire Dragon was the last Nancy Drew book printed with a dust jacket. For Nancy Drew, Fire Dragon is the last title listed on the back cover for first picture cover editions. For the Dana Girls, Sierra Gold is the last title listed on the back cover for first picture cover editions.
Furthermore, when Nancy Drew first picture cover editions have an interior list, the last title listed is usually
The Clue of the Dancing Puppet, which is the first Nancy Drew book that never had a dust jacket. Some Nancy Drew first PCs list only to Fire Dragon on the inside. Nancy Drew picture covers that list to Moonstone Castle on the inside are not first PCs.
Likewise, the first Dana Girls picture covers list Nancy Drew to Dancing Puppet. I do not know whether any Dana Girls picture covers list only to Fire Dragon; the ones that I have all list to Dancing Puppet. The Dana Girls PCs that list to Moonstone Castle are early PCs. With this in mind, the listings in Farah's Guide can help collectors figure out the characteristics of the first PCs of the Dana Girls series without having to have a detailed Dana Girls guide.