[Raf]

I think I agree. Their are some slight contusions of metal on the inside at the base and peak of the comb that could be gas welds but it is genuinely difficult to be sure. As you point out you would expect to find a lap rivit at the peak where the two halves join. Apart from this their doesn't seem to be any other use of modern welding techniques where you might expect to find them . Everything appears to be largely hand raised and shows genuine skill. The problem with all these helmets seems to be that everything is a bit too uniform. The metal doesn't show the uneveness, flaws , inclusions ect you expect to find in an object of the implied date.

So here is something that looks all wrong but I think is right. Described by an auction house as a copy of a seventeenth century funeral helmet . The crown looks recycled from a genuine munitions helmet , the spike looks convincing and the visor has the the comical absurdity that these later funeral helmets seem to have.