i like to start pulling the piano apart when recording our uprights. You can pull the plate off the front and over the hammers. I like the increase in the attack it'll give. Try micing the wood behind, listeninor stereo. I once taped an sm81 under the hood up top, closed it down for the sweetspots for bass and treble notes. Also, you can try micing underneath the keyboard where the strings resonate. I've had luck with at4033's / 4050s, sm81s, and akg 414's. We have a lawson l47 that sounds great on piano in mono, placed overhead a couple of feet, pointed down at the exposed hammers. Depends on the material i suppose (whether mono or stereo). Once tape an sm81 under the hood up top, closed it down, and tracked drums and piano live. Made for an interesting drum piano combo =) although not much separation. good luck! the piano sounds like a nice piano, so you can't go wrong, just watch for phasing with multiple piano mics / front,back which you already know
scott
