Okay then. Since I don't have a side-view photo I used another - you get the idea though. Now the shaft is i little complicated so bear with me.
7.5mm is depth of shaft without the screw in this photo:
When I first put it on the empeg without the screw it sat too close to the fascia and so I found that the most I needed to adjust the depth so that it would work properly is
6.0mm and that is the way I left it. You may also want to note that now has a
1.0mm clearance from the fascia.
Here's the measurements:
I hope this info helps you out. Please keep in mind that getting the alpine knob on right is a bit tricky.