I cannot claim that this list is necessarily complete. The Royal Danish Library has only recently purchased a collection of von Klenau's manuscript scores but has not got very far with cataloguing them. The 8th and 9th symphonies turned up in a house in Vienna only a few years ago.
PAUL VON KLENAU: A CATALOGUE OF THE ORCHESTRAL MUSIC
1908: Symphony No.1 in F minor: 37 minutes + (Dacapo cd)
1911: Symphony No.2
1913: Symphony No.3 for soloists, chorus, organ and orchestra
Symphony No.4 "Dante-Symphonie"
1915: "Gesprache mit dem Tod"-Six Songs for contralto and orchestra: 14 minutes + (Dacapo cd)
1916: Ballet "Klein Isas Blumen"
Symphonic Fantasy "Paolo und Francesca": 19 minutes + (Dacapo cd)
1918-19:"Die Weise von Liebe und Tod des Kornetts Christoph Rilke" for baritone, chorus and orchestra: 71 minutes + (Dacapo cd)
1920: Ballet "Marion"
1922: "Jahrmarkt bei London"("Bank Holiday-Souvenir of Hampstead Heath") for orchestra: 17 minutes + (Dacapo cd)
Violin Concerto
1934: Altdeutsche Liedersuite for orchestra: 17 minutes
1938: Festsymphonie
1939: Symphony No.5 "Triptikon": 11 minutes + (Dacapo cd)
1940: Symphony No.6 "Nordische Symphonie"
1941: Symphony No.7 "Die Strumsymphonie": 32 minutes + (Dacapo cd)
1942: Symphony No.8 "Im Alten Stil"
1945: Symphony No.9 for chorus and orchestra