Strange dagger ... can someone ID?

[fernando]

This is a hell of a coincidence ... or not?
From the collection of R.D.C. Evans, we can see in his written work, this interesting specimen, with a rather intriguing ring, in a fashion similar to the one presented in my knife.
The author considers (and i quote him) that the purpose for this hole is obscure, if indeed it has a practical function. On a second thaught he wonders if its use could be that of inserting the firearm's ram rod, to help loosening the bayonet from the gun barrel, when it gets stuck.
Obviously such purpose wouldn't suit my knife, as it certainly is not a plug bayonet. But i thaught it was interesting to bring here this case of similarity.
Evans dates his bayonet as being from the early XVIII century, and he thinks is possibly Basque.
Fernando

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