Ah.... A thousand pardons.... I neglected to post that the piano was taken. Ygmir picked it up, and he has fabricated a fabulous base that replaces the original legs. The new legs are three giant tree stumps. The piano is intended for the staff kantina of the Gate, Perimeter & Exodus Department, but if a "civilian" is a piano- or tree-trunk- aficionado, just ask Ygmir or me and we will teach you the secret handshake. Specially if you can play the silly thing!
Even better, if you can tune it (if it seems to need it). I plan to place a tuning lever and a mute with the piano, but I lack the skill.
Julien, you have a great idea! I brought two upright pianos in 2010. One I put on wheels so it could be pushed around on firm playa without getting stuck, and I placed it permanently in a bar. The other I built a cart for so it could be towed behind a small Mutant Vehicle or a multi-person pedal-vehicle, and this one I moved to different locations every day. Good fun was had with both pianos.
The one on the cart got rained on, and then it fell off the cart, so it was "a wee bit" out of tune after that, but only Dr. Pyro noticed.
But these were full size uprights, which weigh something like 500 or 600 pounds (very rough guesstimate). (Roughly half that many kilograms.) For toting around on Playa I would suggest a smaller piano, the kind with the action below the keyboard. People often call this style "spinet", although it is not actually a spinet in the traditional sense. I don't know what they are officially called, but the top of the piano is only something like 6 or 8 inches (15 - 20 centimeters) above the keys.
I don't suppose you plan to build your Mobile Piano Station for this year? Not much time left. But if you think you can still get it done for this year, I would suggest you look for the "spinet" piano on Craigslist. You might have to pay a few bucks for a spinet, whereas the big old uprights can often be had for free. But you don't want it to get too awfully stuck in the dust.
And.... Sorry, but I have no time to help you build or transport it.