Sale records from Nazi-era auction house Adolf Weinmüller, which trafficked in art looted from Jewish owners, are available online at Germany’s Lost Art Database.
A member of the Nazi Party since 1931, Weinmüller absorbed two Jewish-run auction houses: Munich’s Hugo Helbing, and Vienna’s Samuel Kende. Weinmüller's clients included Martin Bormann, Adolf Hitler’s private secretary.
In 1958, Weinmüller sold his business to Rudolf Neumeister. In 2013 a Neumeister employee discovered the catalogues, which it lent to the Zentral Institut für Kunstgeschichte (the central institute for art history) for publication on the Lost Art website.
Sarah Cascone, writing for Artnews on May 29, 2014, pointed out that "Given the large number of records, it seems plausible that the Weinmüller catalogues could lead investigators and Sunday provenance sleuths to the next Gurlitt looted art trove."
"Some 34,500 objects were sold by Weinmüller during this period in 33 Munich auctions and 18 Vienna sales."
These can now be consulted at http://www.lostart.de/Webs/EN/LostArt/Index.html%3bjsessionid=F952AF9A3892DCD735351DEF55CF8946.m0
Article from Artnews by Sarah Cascone, "Now You Can Browse Nazi Auction Catalogues for Looted Art Sales" published May 29, 2014