Cool, thanks for this tutorial. The mapping works like a charm.
By the way: I find the "correct" Xorg.conf.d way not only more complicated, but also less stable due to the fact that the USB ID changes if you ever plug your mouse into another usb port.
In the lazy xinput way the Mouse ID changes aswell, but I find it much easier to just grep the id dynamically out of the xinput list and then run the command in a startup script.
So the way I do it is:
xinput --set-button-map $(xinput list|grep -i "evoluent verticalmouse"|grep -o "id=[0-9]*"|grep -o '[0-9]*') 1 3 3 4 5 6 7 9 2 8 11 12 13 14

Probably the grepping could be done a bit more elegant, but it does the trick.

Regards Lukas