He adds quite a lot of things.
I think there were at least 10 different things besides the added intro and very different ending.
I have the impression I am the only one in this thread who has really played and recorded this piece. With that "qualification" I would like to correct you and tell you what Kempff really added or changed - namely only very few and minor things as I already said in my earlier post here:
- he repeats no. 3 (plays it two times)
- he adds three or four additional notes in the left hand in no. 4 at 1:21
- he adds two b-flats in the melody of no 5 at 1:41
- he repeats no. 6 (plays it two times)
- the ending is not "very different", he just splits the fourths into repeated eights and plays full chords in the last repetition of the "refrain".
That's all. The rest is Beethoven's original score.
@Mark Hunter: Kempff died in 1991. That means all his works and transcriptions are under copyright worldwide, so none of his sheet music will be on the IMSLP. However, I have found his recordings of Beethoven's sonatas on the IMSLP, all marked Non-PD US - Non-PD-EU, and some of Kempff's sheet music (but not the Ecossaises) on other websites that do not care for copyright.