I just noticed this thread. Interesting ideas. I still see "m a r t" as the letters, as did Tolfo. An abbreviation, perhaps, as there does not seem to be room for the rest of "martiano," whom Tolfo says is being identified "con un heretico," with a heretic. (This is in addition to her identification of the king as Nino.)
In the first sentence of the same paragraph, speaking of the CY (which she thinks was done in 1428), she says that Marziano disappeared in 1425, instead of the usual account that he died then (http://www.storiadimilano.it/Arte/carte_gioco.htm
""Il mazzo era stato molto probabilmente realizzato al più presto in occasione delle nozze tra Filippo Maria e Maria di Savoia , celebrate nel 1428 , quindi almeno tre anni dopo la scomparsa di Marziano da Tortona."
(The deck was probably realized quickly at the wedding of Filippo Maria and Maria of Savoy, celebrated in 1428, so at least three years after the disappearance of Marziano de Tortona.)
The implication is that there is something mysterious about Marziano's disappearance from the scene. She also associates the Empress figure in that deck (the CY) with Barbara von Cilli, whom she says had "eterodosse" beliefs, denying the existence of heaven and hell, angels and demons, while she and her husband founded the "order of the dragon," which was later associated with the Dracula legend, "Dracula" being Romanian for "dragon":
"Se l’Imperatore è Sigismondo, allora l’Imperatrice dovrebbe essere la moglie Barbara von Cilli, sposata nel 1408. Barbara ricevette però nel 1414 solo la corona di Germania e, dopo il Concilio di Costanza, perse ogni credibilità istituzionale per le sue posizioni religiose molto eterodosse, visto che negava apertamente l'esistenza dell'inferno e del paradiso, degli angeli come dei diavoli. Il fatto che fondò col marito l'Ordine del Dragone (Dracul) e che, ancora in vita, godesse di una reputazione molto discutibile (veniva detta la “Messalina di Germania”), contribuì a creare intorno a lei la leggenda della prima vampira."
(If the Emperor is Sigismund, then the Empress would be his wife Barbara von Cilli, married in 1408. In 1414, Barbara received the crown of Germany, and after the Council of Constance, she lost all institutional credibility because of her very unorthodox religious positions, given that she openly denied the existence of hell and heaven, and of angels as of devils. The fact that she with her husband founded the Order of the Dragon (Dracula) and that even in life, she enjoyed a very questionable reputation (she was known as the "Messalina of Germany"), helped create around her the legend of the first [female] vampire.)
Messalina was an early Roman Empress, wife of Claudius, with a reputation for both promiscuity and murderousness (http://en.wikipedia.org/wiki/Valeria_Messalina
Also associating the Faith card with heresy, is Kaplan, Vol. 1 p. 91. He says of the figure on the Faith card, "Beneath her throne is a crowned king, possibly the figure of Heresy." He gives no source or further explanation.
Kaplan says on the same page, of the Charity card, "beneath the throne at the bottom left of the card, is a crowned king, suggesting King Herod." Again he gives no source or explanation. Presumably Herod was not charitable when he slaughtered the Innocents, the opposite of the nurturing figure on the card.