The reference article about Mozarts pedal piano is by Richard Maunder and David Rowland, "Mozart's Pedal Piano," Early Music 1995/2, 287--296; it contains the documents, an organological essay and music examples.
Here's the link for Oxford UP logger-inners: http://em.oxfordjournals.org/content/XXIII/2/287.citation

The historical references (a letter by Leopold Mozart and some other documents) refer clearly to a fortepiano pedal that was put on the floor under the usual "Flügel" (which was the--surviving--1781 (or 1782, I forget) Walter 5-octave fortepiano that Wolfgang owned). The pedal was "about two feet longer and astonishingly heavy," says Leopold. On p. 287 of said article is a facsimile of the autograph of K. 466, bars 88--90, that show the stray bass notes that can't be played on a single-keyboard piano, other than with the pianist's nose.

As to whether Mozart played from the score or not: seen his enormously high production in these years, and within that production, of difficult piano concertos for his own use, it is extremely unlikely that he did _not_ play from the autograph. He probably scarcely had time to rehearse the stuff, and even less to waste time for learning them dot to dot by heart. Playing from memory wasn't an established practice then anyway. Beethoven actually rebuked the young Czerny for doing so...
Whether Mozart used a page turner or not is a whole 'nother matter...

Tilman

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