I really appreciate the effort you put into this, that display really sticks out in a bad way. Designing some kind of fairing would be great, but I think it will be hard coming up with something that in itself doesn't stick out just as much as the display itself since it's mounted so high up and far forward. But I'd be happy to just get some kind of bug protection for the back of the display, so just a small piece of plastic that looks nice as well

Don't know what the easiest way to mount it would be though, if you don't want to drill holes in the original parts... some kind of adhesive?
Instead of a fairing, there's two other options I've been considering. Don't know yet which one would be doable.
First option - Replace the whole plastic box with the same parts for the Vitpilen. Headlight mount, the fairing around it, the back part of the same box. If the parts from Vitpilen fits, you'd get the same clean look with the almost horizontal display mount. But again, haven't looked into the details yet to see if it's actually doable.
Second option - Cut off the display mount and secure it with an adjustable mount so you can set the angle as you wish. Here a 3d printer would come in handy to cover up the gap that cutting off the mount will introduce.
I'd get a new spare part plastic box for this, so I don't have to cut in the original parts. I always like the option to change back to original if I would like to do that in the future.
But considering my track record when it comes to actually following through on the ideas I get, I'm pretty sure I'll never try any of these two options myself

Which in many cases probably is the best option