Well, don't hold your breath. Here's the synthmuseum writeup on the 16-voice piano:
"This was Arp's ill-fated electric piano, which was introduced in 1979. Because of its poor design (the heat-sensitive Mylar insulation in its membrane switches and its noisy output), its after-sale repair costs pushed ARP furthur into debt. It features 16 preset tones, called voices, (hence the name 16-Voice) such as acoustic piano, vibes, harpsichord, harp, and electric piano. According to literature, "A 73-note standard wooden keyboard, with a specially designed and weighted maple action, faithfully reproduces the feel and response of traditional grand pianos." Velocity, however, only controls volume and not timbre. The 16-Voice consists of two separate tone generators which can be detuned to fatten up the sound, up to a quarter of a semitone. The ARP Piano also contains a six-stage stereo phase shifter, vibrato, and two solid brass piano pedals, the right controlling sustain, and the left assignable by a dual-purpose switch on the panel to be either a soft pedal (which also reduces the brightness of the sound) or a momentary vibrato peda"