Ruark R1 Digital Radio knob

Ruark R1 Digital Radio Knob and screw cover.  Not sure which one will best fit as my calipers are a bit rubbish, so I've uploaded a 6mm, 6.25mm, 6.5mm & 7mm hole.  The hole on the original has some small splines which I couldn't be bothered to replicate, so reduced the number of circle sides to add friction.  This could be glued on, ideally printed in ABS which is what I suspect it should have been printed in to begin with.  I used PLA.

The 6mm appears to do the job, the rest were a little too loose (though frankly when you looked underneath, the hole on the original looked a lot bigger!