Very cool. This is something schools should be doing, we have a real lack of bare bones low level knowledge of computers in the world. It just seems second nature to me to know about bits and bytes, but many "younger" professionals don't actually have a clue. This scares me!
If you are feeling nostalgic on the 40th anniversary of the launch of the Sinclair ZX80, why not build your own with a Minstrel 2 kit. (or a Minstrel 3 if you prefer the luxury of a ZX81 compatible kit).