Inspired by Piotr Bugaj and his TZXDuino Shield I thought I'd take his PCB design and add the 2.5mm socket and some right angle buttons and get it so it will fit into a PP9 case. This is a whole new thing for me as I have never designed a PCB in my life or used Diptrace before. Luckily it's quite an intuitive piece of software that's easy to use. After adding a design for a PCB mounted 2.5mm and also the buttons I managed to design a PCB that should work. Now however it's finding a reasonably priced manufacturer for a couple of prototypes before maybe a production run. If you're interested in looking at the Diptrace and gerber file you can download them from here.