I rewatched a clip recently of China Crisis recounting their time working with WB, and there was a bit about Walter "blowing them away" with a keyboard part he wrote. By their (cheeky) telling, his playing was on par with Liszt's.
Which got me thinking: How was Walter as a keyboard player? Obviously the keyboard was an important part of his compositional process post 1980s, and we've heard sequenced parts he's put down, but that's probably about as much as there is out there. Did he have a piano in the house? Take the playing seriously?