It’s a losing game trying to make a piano with subtractive synthesis, but come to think of it Roland’s GR700 guitar synth (and mks30 rack synth) managed to do a basic but recognizable honky tonk piano preset. Unfortunately no way to reverse engineer the sound, but I think it had something to do with their special oscillator cross modulation on an otherwise typical 2 oscillator synth. That and the Juno 106/ Boss Dimension C type chorus, that pitches one copy of the sound up, and pitches another copy down, to make a “motionless’ chorus that sounds like detune.