kiwimew:
Here in New Zealand, I used these buttons http://www.jaycar.co.nz/productView.asp?ID=SP0603 and this case http://www.jaycar.co.nz/productView.asp?ID=HB5970. I've attached a PDF of the faceplate and drilling guide.
Thank you for posting that; its really a great looking project - heck, it deserves to be a kit! It would complement the "mini-Altair" emulation kit that's out there (which uses a PIC processor, IIRC)...
