Dear Mr. Robert Messenger, to the auther or editor of oz.Typewriter and to the readers.
Wouldn't you name the machine on Parkinson's paper:"The Dvorak Simplified Keyboard: Forty Years of Frustration" ?
key or typehead of typebar or arm, in Parkinson - QWERTYの史的とぐろ？raycy - qwerty-history-jpグループ
The Dvorak Simplified Keyboard: Forty Years of Frustration, by Robert Parkinson, Missisauga, Ontario
From Computers and Automation magazine, November, 1972, pp. 18-25