The Mk.1 has the buttons on the left because, errr, well it just happened that way! Maybe Hugo & Patrick did some research, I don't know, but that's how it was :-)

The Mk.2 still has the buttons on the left and the rotary control on the right because we want the panels to be compatible (put a blanking gromet in the hole for the rotary switch and you have a panel suitable for a Mk.1 - useful if people want to change colour in the future).

Rob