Walther Löbering was an artist and visual observer who had lived in Germany from 1885 to 1969. His granddaughter Mrs. Ulrike Toll kindly provided his planetary drawings
in 2015, and I scanned and indexed them. You can download the resulting ISO file below. It comprises Löbering's observations between 1916 and 1963, mainly of Jupiter,
plus some peripheral correspondence found in his inheritance.
Download (~1 GB!)
Further 727 Jupiter drawings Löbering made in 1929 are located at the Archenhold Observatory Berlin and part of their database. You may visit an exhibition about Löbering's work at Leubnitz Castle, not far from Fasendorf where he used to live and observe.