I certainly don't deny that there were depictions of such hats contemporary with the proposed date of the CY (1441-1447), such as the depiction of Farinata in the Villa Carduci, c. 1450, the image you displayed last. But Farinata was of the 13th century; in 1450, that is the distant past. You don't give the context of your other exhibits, but I suspect that they are meant to depict events in the distant past as well; that's what frescoes usually did. If they are meant to depict recent events, what you say would be more believable, but even then I would question whether they actually wore such hats in battle; it would make the commanders rather easy to find for the purpose of killing or capturing. They might have worn such hats, of lesser size perhaps, on special occasions, to make it easier for the people--and viewers of frescoes--to identify them.
Looking in Roettgen's Italian Frescoes: the Early Renaissance
, I see several fresco series with such large hats. They all depict historical scenes. Also, such hats are shown as early as 1416, in a Crucifixion
by the Salinbeni workshop in Urbino (whose leader, Lorenzo, died before 1420, per Roettgen). I give a detail below, primarily for the intricate designs on the dresses (this is from a Crucifixion, with Roman soldiers).
http://2.bp.blogspot.com/-7SlSB6sMdLg/U ... enPl25.JPG
This is right when Bendera said such clothing stems from in Milan--in frescoes, that is. Real life is another matter, although the dresses are credible enough, then as well as later, and hats of more modest dimensions,e.g. in the Tres Riches Heures
of du Berry, 1414-1416 (Roettgen p. 43), of a procession.
http://4.bp.blogspot.com/-lAm_Ptk3pkI/U ... ig6p43.JPG
As far as the larger hats and where they were worn, if at all, I'd need to know more about the context of the pictures you present: what it is meant to show, and where it is. Perhaps then we could say whether such attire would have been considered suitable for young Jews on their wedding day in 1438.
However I can't see that anything hangs on this, whatever the truth. The fashion for such depictions started around 1414-1418, not much earlier, because a 1350-1360 Crucifixion in San Gimignano (Roettgen p. 62), similar in composition to the 1416 in Urbino, shows no such hats.
http://3.bp.blogspot.com/-Xue86AMMPoU/U ... .%2B25.JPG