I have had this book for at least 20 years. This is a service manual of Chinese typewriters, namely, Hero, Flying Fish portable, Chang Kong and Flying Fish desktop.
As you can see, it is in Chinese, but some of the drawings are amazing. Any fellow typospherian interested in reading it? I can send it/share the pdf file of this book. In China, IP for books is around 20 years. This book was printed in early 1980s. So IP protection has long expired for this book.