Not exactly ‘archives in fiction’, but close enough, is something I just found in Julian Barnes’s meditations on death, dying and family history: Nothing To Be Frightened Of.
After a long disquisition on what little remains in the family and public archives for his grandfather, he makes the following observations:
A Bertie who changed into a Bert; a late volunteer; a mute witness; a sergeant discharged as a private; a defaced photograph; a possible case of remorse. This is where we work, in the interstices of ignorance, the land of contradiction and silence, planning to convince you with the seemingly known, to resolve – or make usefully vivid – the contradiction, and to make the silence eloquent.
Whether he is commenting on his work as a novelist or as a writer of literary non-fiction, what he says is so accurate a description of what those of us working in family history (and history more generally) attempt to do, especially when we are delving further back than direct memory allows – faulty as that is, too. He is a great deal wiser than those historians who try to assert that what they have to say is ‘the truth’, and it too is ‘nothing to be frightened of’.
 Julian Barnes: Nothing to be Frightened Of, Vintage Books, London, 2009, page 240