re: arcana & incunabula

> you might be surprised to learn that the essential design of this
> keyboard was invented & patented by Hermann Leudtke in Germany in
> 1932

Hello,

Hans Luedtke secured UK patents 390,574 (Improvements in an orchestral
instrument, 1933), 413,483 (Improvements in and relating to musical
keyboard systems, 1934) and 459,900 (Improvements in keyboards or
arrangements of sounding bodies for musical apparatus, 1935).

Clark