After having to dismantle my project for a year while I moved house and renovated, I'm pleased to be able to share a photo of the final working build with you. A full description of my project along with many more pics can be found here https://paultownleyjones.wordpress.com/2015/10/06/how-to-build-an-arcade-machine/.
I'm yet to get MAME up and running on it, but this will be next on the list. Any pointers on good interfaces and install instructions? Having tried to install and use MAME once in the past I remember it not being very simple.