Yeah, I know this is an old thread.  There’s a lot of info on the net about Elton’s sound and it boils down to a midi’d Yamaha grand being used as a controller going to layered MKS-20 “Piano 1” and Motif “Power Grand” sounds.  The MKS is the body.  The “Power Grand”, possibly the brightest piano on the planet if you raise the HPF, is the bite.

As an experiment I layered the “Analog Piano” as the MKS20 sound along with the “Power Grand”.  HPF on all elements of the Power Grand were turned up to 230.  I didn’t settle on a “bite to body” ratio but even equal volumes worked.

I was listening through headphones and I haven’t had a chance to test this at a jam, but it sounded like one hell of a rock piano to me.  Let me know what you think.