Another thing that strikes me as similar to the Petit Oracle, besides Etteilla and de Gebelin/de Mellet, is something else, namely, the Minchiate. This has been talked around, but I can't find where it has been spelled out.
If you look at the writing on the cards, you will see that almost every card of the Minchiate is represented, one way or another, in one of the images of the Petit Oracle.
First, we have all the tarot trumps that the Minchiate took over, including both a "Hermit" and a "Traitor" but no Grand Duke, and instead of the Emperor and Empress we have Jupiter and Juno. (The Grand Duke might be the "Law" of "Law and Faith".) For the Tower, we have the Prison image, as in Etteilla. Then in addition, we have Prudence, Hope, Faith, and Charity, all of which are in the Minchiate. Minchiate's four elements are named on four of the cards that have other names. So are the 12 signs of the zodiac. And there is a Fame card (Renommée) as well, in both Minchiate and the Petit Oracle. I believe that covers all of the 41 cards of the Florentine Minchiate.
The obvious link is Poilly's Minchiate Francesa of 42 cards (the same as the Petit Oracle, with a somewhat similar 12 + 20 schema, zodiac plus others vs. single image plus double image, as Huck observed). Here are some of Huck's descriptors of the first 21 cards, along with his posts of cards in the Petit Oracle. I am not claiming an exact match, to be sure, just some resemblance. Some unfortunately are upside down.
02 L'amour (blind flying Eros with arrow and flowers)
C. 1800, most tarot images of Cupid weren’t blindfolded.
03 L'Esperence (woman at small island with big anchor; Hope)
05 La Fortune Woman standing on wheel in the sea; wings at her feet)
This is in addition to the Etteilla image of Fortune, which on the card, too.
07 La Charité (woman with two children)
09 Les Ages, la Vieillesse
10 Age Viril (hero with sword and shield and dragon; "Golden Vlies" in a tree)
Of course here the Lenormand deck is closer.
http://www.britishmuseum.org/resear...px&numPages=10¤tPage=2&asset_id=1102156
11 Ages Adolescences (3 young women and a young sitting men reading from a book)
Well, there isn’t any exactly like that in the Petit Oracle, just one person reading a book or a group of young people talking.
12 Ages l'Enfance (three naked children playing "hiding")
15 Element Terre (woman in landscape with fruits and with baton and crown)
20 La Renommée (Angel with trumpet; Fame)
These are just from the first 21 descriptions that Huck gave. They have nothing to do with Etteilla that I can see. I couldn't find Huck's descriptions of the other 9, before the zodiac.