I seem to recall reading of a deception of this sort that took place
in real life. The trouble is, I've read a lot of "true life" espionage
books, and the details start to run together. I know that someone once
proposed this as a solution (albeit not a very likely solution) for
the Valentich disappearance, but that's not the incident I'm trying to
recall here.

Is my memory playing tricks, or was there once a case where someone
connected with some intelligence agency faked his death?

Sidney George Riley, perhaps. He was called "The Ace of Spies", and some
even believe that he was the model for James Bond. And, on-topic, some
believe he faked his own death.

I believe that some people feel that Glenn Miller's death was faked. I
don't know know anything about that, though.

An even more pertinent question would be this: do intelligence agencies
have a track record of faking events or information in order to bring
about a desired outcome?

The resounding answer is "yes". Every major intelligence agency does
this on a regular basis. And, yes, the CIA and Mossad do it just as
often as everyone else.

If you really want to have your mind blown, do a Google search on
"Operation Northwoods".

Have fun! Does any of it sound familiar?