Ross a long time wrote from a person H. Chobaut, who made researches in 1955. This author is mentioned in the book for 5 times. One might have the suspicion, that the text is from him ... but no confirmation.
at a webpage I read, that the author Henri Chobaut worked for Provence historique. Maybe Henry Chobaut was on his way to detect this, what we see here, when he wrote the article with the 1507 date. Depaulis was 6 years old, when the book appeared.So one could possibly easily overlook this 2nd book, perhaps just assuming, that it contained the same article with the 1507 dating.
For a long time, it was believed that Rabelais' mention was the earliest. Thus I was shocked the first time I read an article from 1955, which mentioned "taraux" in 1507!
In 1955, H. Chobaut published a study of Avignon cardmakers, and noted the phrase "cards commonly called taraux" in a contract from 1507. However, he did not provide a transcript of the full document, or its catalogue number in the archives.
Chobaut's work went unnoticed by most tarot historians, and he is not mentioned by Dummett in 1980, Depaulis in 1984, Berti and Vitali in 1987 etc. However, at some point Thierry Depaulis re-read it and decided to go look for the original to confirm it. Dummett noted in 1993 (Il Mondo e l'Angelo) that Depaulis had at that point been unsuccessful in his search.
Sometime later, it appears that an archivist in Avignon in touch with Thierry did find the document referred to by Chobaut - however, Chobaut had misdated it: it was actually from 1505!
Thierry put this information in an article which was published in 2004 in The Playing Card. He also believes that the term "taraux" is French (not Occitan), and probably comes from Lyon, and that "tarocchi" is an Italianization of the French word. I don't know why he thinks it is a French and not Occitan word, except perhaps because he is certain that the "x" was silent, as it would be in modern French.
I'm not so sure; and in any case, the original document was in Latin, so I would expect a "phonetic" transcription of the word. Thus I believe the original pronunciation of the word was something like "tar-oaks". This would explain also how the Italian word came about.
Incidentally, the Italian researcher Adriano Franceschini discovered the earliest mention of "tarocchi" in Ferrara records also from 1505! (he discovered this probably over a decade ago, but few knew about it). The Avignon record is from December, the Ferrara (there are two) are from August. Thus, by 1505 the two different forms of this word were already in circulation.