And no we're not taking the piano version of the violin concerto, but rather Piano Concerto No. 0.
Pianist Kuerti has been busy working on a reconstruction of an early Beethoven piano concerto
he has been reconstructing a 6th piano concerto written by Beethoven at the age of 14, which only exists in a single-piano reduction.Link
If interested, you can find a midi file and some concise background on this work at one my favorite spots on the web for all things Beethoven: "The Unheard Beethoven Project" Link