It's been a while since I've read Petersburg, but it would seem to fit your criteria.

There are more radical challenges to the notion of a single valid reading (Rayuela, Marc Saporta's Un, The Dictionary of the Khazars (and a few others I can't remember right now).

And of course there are pre-modern books that seem modernist or at least predictive of modernism (Don Quixote, Tristram Shandy).