I am very interested in getting a response to this question. The helmets are German, from around 1430, and consistant with drawing of helmets from other books, but to my knowledge there are none of these in any museum I know of.
I can see an armet, there is one with a similar hight neck and a rounded pierced visor. The roundel could even protect a hinge to allow the faceplate to be removed like a bascinet. The other thing they might be is a closed helmet with bevor or wrapper pivoting on the same hinge as the visor. This is what my wife sees.
Could it be
A great Bascinet? This one is from about 1440. it has a good foot combat visor on it. It even has a catch.
An early Armet.
There is only one of these. It is German from about the same time period as the paintings. I think it is the most likely possibility
for these helmets, but where are the rondels?
Something we have no extant versions of.
Here are your rondels. What is it, it is an artists rendering of something dawn or carved. There are more. Has something in common with the pics.
Very good question wouldn’t you say?