Great article! I really love electro-mechanical designs from the birth of electronics up to the 1960s. Using a little hammer to strike two bells is such a simple, cool, and intuitive design. Today it would be replaced with a piezo buzzer or speaker which works, but isn't nearly as interesting.

You don't really see cool little designs like that anymore - it's all almost all digital now. Though I will say YIGs and RF designs are pretty cool in terms of combining mechanical with electrical elements. Maybe it's just nostalgia, but I miss when electronics weren't so standardized. Tube amps, flip displays, tube displays, etc.