[Peter Dekker]

Agreed, a north Vietnamese trường đao (長刀).

Typical Vietnamese features are the very dramatic widening in width combined with the concave clipped tip. Also the small guard and its decoration point towards northern Vietnam.

The wrap is indeed fairly recent. Apart from the type of cord, it is also the way the cord is wrapped at the pommel that looks like: "I don't know what to do here".

It looks like the hollow part of the guard is directed towards the pommel. Is this the case, or is it massive and just this thick?

As for the executioner's attribution, there are some photos made around 1900 that do show these in the hands of Vietnamese headsmen.

EDIT: I had originally attached pictures of three headsmen with such swords, but someone complained that his grandson was also browsing the forum and kids don't need to see it. I respect that.

But I believe that like in China, there was a degree of freedom as to what weapon would be used for this purpose. You also see Chinese executions performed with the dadao, even though it was not the weapon's main reason for existence either.

Some of these come in pairs with a smaller and a larger one, and I have also seen them with damage from other blades that indicate they were fighting weapons that sometimes were also used for executions.

Ren Ren: Fascinating info about the Vietnamese creepers! I quite like the work, especially in mother-of-pearl, but had not been aware of their significance.