Criminal Sentence 338: Two Naughty Prepositional Phrases

From a book about Anne Boleyn:

"He wrote an account of what he had seen in 1559 in a letter to Elizabeth I."

The sentence is supposed to say that the man wrote a 1559 letter to Elizabeth I and in this letter was an account of what he had seen earlier than this date, when Anne Boleyn, Elizabeth's mother, was alive.

The sentence makes it seem that he saw something in 1559 and that thing was in a letter to Elizabeth I. In other words, the two "in" phrases are incorrectly placed. Let's rewrite it:

"In a 1559 letter to Elizabeth I, he wrote an account of what he had seen."