Thanks for your clarification. What you say is not impossible, at least as far as modifications in the tarot to accommodate the . ideas of "secret Jews." Also, it strikes me that "secret Jews", practicing both Judaism and Catholicism, would be acutely aware of hidden affinities, or imagined affinities, between the two, for example regarding the Trinity. Which of course brings us to the Kabbalah, which some Christians, i.e. Pico, saw as formulating Christian ideas in Jewish terms, or else getting to an understanding that transcended both. In that way the "secret Jews" would not be betraying their religion in adopting the practices and language of Catholicism. Some converts to Christianity who translated Hebrew Kabbalah into Latin might be in that category, such as Paolo Ricci and Flavius Mithridites. I can see certain Christians and Jews collaborating, just as Pico and Yohanan Alemanno collaborated for a short time, without thereby giving up their own religion (on this see the thread on "Jewish-Christian interactions" here). And the tarot could then be for the use of both Christians and Jews who knew the references. My own speculations on this point are at http://latinsefiroth.blogspot.com/
Besides Ferrara, another important place for Jews was Padua, which at the beginning of the 15th century had opened its doors to Jewish medical students. This would have attracted Jewish rabbis, butchers, etc., to serve such students. Padua is of course quite close to Ferrara, and even closer to Venice.
The period between 1500 and Noblet is rather sparse for preserved cards, but there are a few. Mostly they build on a style that developed in Florence, seen in the "Rosenwald Sheet", the "Rothschild Sheet", and "Musee des Beaux Arts," plus what can be inferred from later decks of minchiate (an expanded tarot originally from Florence with 40 triumphs plus the Fool) and tarocchini (a Bolognese varient that omits some of the number cards). All these, however, are rather different from the type of deck you call the "deck from Ferrara."
For that "Ferrarese" type, plus a type more directly connected to the Noblet called the "Cary Sheet", c. 1500, you should look at the chapter in Kaplan's Encyclopedia of Tarot
, vol. 2, Chapter XIV, on "fifteenth to seventeenth century tarot cards". These are mostly on sheets that never were cut up into cards but used instead as filler in book binding.
After those, for antecedents to Noblet, you have to go to other French decks. The Catelin Geoffroy, 1557 Lyon (see http://cards.old.no/1557-geofroy/
) for the Hanged Man actually has what appears to be a Jew, at least according to some, hung upside down but with both feet tied to the rope. It strikes me that it could also be Jesus, whom the Talmud (Book of Sanhedrin) says was "hung from a pole", or some other heretic from Judaism. There is also, on the same website, the "Anonymous" tarot of Paris, which looks to some as though it were influenced by Ferrara, before tarot ceased being played there, in the late 15th century when the Papacy took Ferrara over. And finally there is the "Vieville" tarot, which has more affinity with the Cary Sheet than the Noblet. And after the Noblet the tarots of Dodal and Payen have more affinities with the Noblet than what came later.