Nomadic swords

[ariel]

Well, it depends how one looks at it:-)
As you say, the 2 panels may be a "clasical" tunkou with a separate inscription panel, or an analogy of a "Chinese" tunkou with a slit in the middle.
But how about my own example? It is dated 1217, the koftgari is worn and partially lost, but the base-located wall-to-wall decoration and the " upside-down" orientation of a very long inscription at the top is obvious.
And, of course, one should not forget the tunkou on the great majority of Persian khanjars and the yataghans from Turkey: they all have the "upside-down" pattern. In the latter case, tunkou became just a triangular element with the long side along the spine , including just the cheap crude incision of the outlines.

My point is that with time the orientation of tunkou flipped over from the edge-located to the spine-located. What was the reason I have no idea, but a placement of long inscriptions along the spine fits nicely with the general idea.