Chafez Chayim checked copies of (which) books?

Question

I've heard that the Chafetz Chayim inspected each page of each printed copy of the Mishna B'rura to be sure that it was printed correctly (with no large ink splotches or the like).

• Is there a reliable source for this fact?
• Which printings of the Mishna B'rura — and other books, if any — did he do this to?

Answer 1

http://www.shemayisrael.com/parsha/feinhandler/archives/chayeisa.htm

The Chofetz Chaim sighed deeply and said, "I too am a person who makes mistakes. You know that I sell my books. Sometimes the binder misplaces a page, or a page might be missing or have unclear print. Even though I am careful to check every book before it is sold, there still could be mistakes. The people who buy my books are embarrassed to tell me when there is a defect, but in their hearts they really care, and that is why I was also punished."

This link - from here shows a photograph of a Sefer the Chofetz chaim sold with the word "Mugah" handwritten by the Chofetz Chaim.