Johann Christoph Kellner (1736-1803), Praeludium in C dur.
Sheet music can be found in Incognita Organo Volume 18, editor Ewald Kooiman.
More pieces of Kellner can be found in my playlist:
https://www.youtube.com/playlist?list=PLNFZTCpjQ59UConkh9qnDbG-RFU7cGio3.
Played on
Sonarte organ with Hauptwerk, 2007, Tomaš Močnik, church of our Lady in
Adergas , Velesovo, Slovenia