Hi Gatso
Yes, Delrin.
I drew them on CAD first so I can send you the drawings if you want?
The plugs for the swinging arm spindle use a piece of 6mm diameter alloy rod that goes through the hole in the spindle. It has an M6 thread at either end and the plugs are tapped M6. The 6 small holes you can see in the face are for a pin spanner to tighten them.
The smaller plugs use another piece internally with an o-ring that is squashed and hence expands as you tighten the screw.
I'm working on some for the holes at the very bottom too, but they have a very sharp angle.