[morzh]

So I tried the split pins.
Though the diameter was exactly right, stainless against wood provides very little retaining force.

   
   
   

So I used a wedge tool to split the pin further.

   

The pin then has to be aligned and compressed a bit to start getting into the hole. Or maybe the end of it ground to form a chamfer. Or maybe the wooden hole slightly countersunk at the top. Just to start guiding the wider split pin.

The result is acceptable.

   

At the end, I think it might be a better choice  for this particular goal than the one from  the  Renovated Radios, the reason being, the latter, if does not provide retaining action, cannot be split anymore being plastic, whereas the metal one can.