"Message" implies an actual quote from the man. "Example" would be more appropriate in this context.
A story or experience can have a "message" the same way it might have a "moral". In fact "moral" is often defined as: the message conveyed by a story.
"Example" would have been a poorer word in its place.
are not identical. The former is a personal article or note from Babbage.
I got down voted for exactly what zeteo said...
and "A message from Babbage's life for the middle-aged"
to me both titles sound elegant but the former is misleading and the latter is correct.
The title is not trading ambiguity, it is just misleading.
"Babbage's message" made the title shorter, but also misleading. A complete title of "Babbage's heart-warming" would have made it even shorter, but I hope you're not advocating in favor of that!
Jim did not write a letter. He was the "author" of the sentiment (according to the speaker) by the way he lived his life.