I've now completed the keyboard to the point where I can load and run programs via the emulator, including support for multiple layouts.
I will add the Fn keys next and then hook it all up to the emulator, removing the clunky NSTextField and built-in keyboard. I short video will follow with this milestone.
A longer term usability goal is to show the actual 'drawing' keys when the shift or C= key is pressed, but gathering all the images of the keys is a lot of work for a rainy day.
The default layout:
The number and glyph layout (Fn keys will go here):