The newer versions of the brilliant AxiDraw have changed up the screw pattern for the pen holders to attach to the pen-lift slide. Newer accessories like the italic pen adapter, XL pen clip and the pen clip rotation stage only work with the new screw pattern.
What's a sad AxiDraw v2 owner to do.... bodge together a quick and dirty adapter, that's what!
Two versions of this design are available. One version has the receiver holes for the new 'straight' pattern set at 2mm with the intent that they should be tapped for 3mm. The other has them set at 4mm so you can melt a little threaded insert into it.
I took the measurements by making a charcoal rubbing of the pen-lift and doing some dodgy drafting. Everything seems to line up just fine.