Arno Landmann (1887-1966) was a student of Karl Straube, who called him an "unsurpassable organ virtuoso" and Max Reger, whose inner circle he belonged to.
From 1911 until 1943, he was organist at the great Steinmeyer organ (today 96 IV/P) of the Christuskirche in Mannheim, Germany.
He wrote the Händel-Variations during this period (first version in 1935) and most likely for this organ and it probably sounds most authentic also on the great Steinmeyer organ of Corpus Christi!