Clever Constellation Cards

Stumbled upon these wonderful Astronomy cards from 1830 on ebay ~ aren't these gorgeous? Not only are they beautifully engraved and hand-colored, but they are cleverly designed to instruct as well. The 32 cards came packaged in the box shown above ~ I wonder how much they sold for when they were first produced?

According to the description, these 'hold-to-light' cards were "designed by a “young lady” to make the study of Astronomy “familiar and amusing”. Each card is pricked through with holes of different sizes relative to the apparent magnitude of each star within a given constellation. This rare find can be yours for a mere $2500 obo ~ available for 23 more days here.

I am also curious as to why each illustration has a loose thin outline. Were the illustrations supposed to be cut out and used separately? Or perhaps hung mobile style? Anyone have any ideas or conjectures?