Hello,
I am an NES collector based in Austria and signed up today to answer the question. There are 5 different module cover variants of this game for the smalbox in Pal B and the 5-screw variant shown is real. This was sold in Scandinavia and the 5-screw module is currently selling for around US$45-50 in good condition.
Sorry, it's not realy rare.
Attached is a photo of the existing variants of the game packaging as Pal B in the small packaging.
In France and Holland, the game was additionally sold in a large box, but the cover then looks different.
Greetings from Austria (Europe) rubyhoorn