This is MarkVdB? -himself :-) - speaking. I am a co-owner of the non-profit musicaliberata.org. Sorry about being somewhat unclear about licensing issues. Of course you can use these images. I will release them more explicitly under an open license. This was ment to be part of the meaning of the footer quoted below. Hope you're reassured by this.
A quote from http://musicaliberata.org/ 's footer: "This site and its contents Copyright 1999-2001 MusicaLiberata?.org. Most of the content can be distributed freely under an open license" And a link to the license itself: http://musicaliberata.org/oal -- WP