That nice of a piano deserves some decent small diaphram condensors. Keep this in mind if you're going to be doing a lot of this. With what you've got, I'd probably put the two 57's in an X/Y pattern somewhere a foot or two above the wires. X/Y is where you line up the two mics capsules one over the other with their bodies at an approximately 90 degree angle. Sometimes, a little wider angle works better. Gives you a decent stereo image with little phasing issues.

Any other Python heads out there recall the sketch for the flying school with no planes? Where Graham's mocking someone's snobbery (about the school not having planes) and he says in a very effete accent "Oh, no more scones for me, Mater. I'm off to play the gran' piano!"
-kent