How to fit a Nagel to a hilt
 

Does anybody know how a nagel was fitted to the hilts of lange- and kriegsmesser?

I'm thinking of something like this:
Seems to me there are three options

1) Drive the nagel through the cross guard and the tang and rivet it on the other side of the cross guard.
2) Forge a single piece nagel + cross guard from one piece of metal.
3) Forge weld the nagel onto the cross gurard.

I've seen method (1) done but it seems like a good way to weaken the tang. The swords in our national museum all look to have the tang attached somehow but there is no evidence of them being driven through the tang and riveted on the other side of the cross guard. Normally I'd put my money on method (2), except one of these messers is missing the nagel and you can clearly see the tang through the hole the nagel left and there is no sign of a hole in the tang.

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One could also forge the guard in one piece, drill/cut a hole on one side thru to the tang opening but not into the other, make the nagel (nail) with a stub tang slightly too big for the hole, heat the guard and quickly drive the nail tang into the hole which would have enlarged from the heat, and let cool. A shrink fit, probably as strong as a weld there.