Some help needed for Directmedia import

I could use some help to separate anonymous artists from named ones in 
the metadata. See

http://commons.wikimedia.org/wiki/Commons_talk:10%2C000_paintings_from_Directmedia#Some_help_needed

For general information:

http://commons.wikimedia.org/wiki/Commons:10%2C000_paintings_from_Directmedia

All best,

Erik