Convert your piano to the whole tone Janko system. Fits 164.5mm octave, I can scale to other sizes if necessary.. No screwing or fixing needed, held down by backboard felt, operation is entirely reversible. You will need one of these per octave. Most uprights have 7 octaves, starting from low A. One scale form works for all keys, cut practice time x 12 transpose in your sleep! Try out this system first on http://improvise.free.fr/beanbut/bean.htm
You will see it makes sense!
In this five row "piggyback" model the whole tone row A B C# D# F G is nearest the player and each note has three buttons on one lever. The other whole tone scale (Bb C D E F# G#) has two buttons on each lever. The adaptor levers are joined at the rear by a strip which sits between the piano's two rows of pivot pins. The key measurement to check is 10 cm between the back of the black keys and the first row of pivot pins. If you are handy it would be smart to join all seven octaves of the adaptor with a continuous metal or wood strip which you can slip inside at the back.
If your piano is different (octave width and pivot distance) you can send me a clear measured drawing and a photo of the action without the back board and I can make adjustments very easily.