Thanks guys,
Here is a picture of the final hanging system:
It is unobtrusive, and as the bottom string sustents the center of gravity, it rotates easily to horizontal when I sit or crouch, and there is no risk because of the pin.
another better picture:
All wood is great, the look is less tactical, more utilitarian, much better than kydex, and I even prefer it to leather sheaths. It is safer (if the wood is good) but marginally heavier (if the wood is hard). But it needs a good retaining mechanism, as the friction fro leather, cordura or kydex is absent. (wood moves with hygrometry, so some space for the blade must be made).
I made a few in the past and my main mistake was to have them of a constant section at the mouth, rendering string or leather attachment by knotting difficult, so I had to nail and glue. This one has a larger mouth than the rest of the sheath (in a very adaptated indonesian style), and a string or a piece of leather can hold it without the need to be nailed or glued, which makes it great for repairs.