It's a German style of kettle helm...
Thanks for that Steve
I'd be happy to accept the fig with such a kettle-hat but that's not what's depicted.
The model clearly has a pretty-well straight brim with the nasal projecting at quite a flat angle. Even allowing for his head being tilted upwards it seems strange as it would barely protect his face from a horizontal or upwards diagonal stroke (zone of attack in red below) and a vertical one would exert so much leverage on the nasal that it would surely dislodge the helmet.
Here are shots as is and corrected for his tilted head plus with the helmet brim horizontal (as sources show they were worn), where it then starts to make more sense:
So, I think that, at best, the helmet is raked too far back on his head and, at worst, that the nasal just doesn't make any sense.
To me the remedy would be to bend it downwards so it's more vertical or remove it entirely (my preferred option).
You can't prove a negative, but a trawl through my reference works and
go-to site for contemporary illustrations reveals
531 manuscript illustrations, from all round Europe, none of which show anything quite like this version.
The nearest (plus a modern repro) are:
(1410 Swiss; 1380 Austria; 1370s Italy; 1385 Germany; 1400s Italy; 1360 Germany; modern repro)
Note that most combine a short nasal with a deeper brim and the eye notches as per Steve's illustration. Indeed, it's clear that the nasal is formed by the eye notch cut outs rather than as a separate appendage. The next to last shows a more commonly illustrated style with a sharp downward front peak.
As said, you can't prove a negative, but, until contemporary show otherwise, the helmet as modelled seems unlikely (but happy to be proven wrong).
Nevertheless, it's a great piece/combo and easily remedied (if you want to).
Neil