@Graham Some updated pictures. I opted for a metal briefcase as the enclosure. I have modified a modern NES style controller to act as a two button joypad. I used pin 9 for the second button to keep it compatible with other retro computers that use that standard.
That's good to know I take it it is now working and the teensy programmed to read the keyboard matrix ? Well Done !! P.S is it able to run off a battery supply I can't remember what you said .. better I go and check .