Did anyone else notice how Google is referred to as "advertising giant Google", not "search engine Google" ? An accurate, but unconventional, portrayal.

What I'm wondering is who is attempting to sell the papers?

From the article:

The collection, now officially named the Turing-Maxwell Collaboration Collection, comprises the largest known collection of Turing's offprints in the world - given by Turing to his close friend and colleague Professor Maxwell Newman.

Wikipedia says that Newman passed away in 1984: http://en.wikipedia.org/wiki/Maxwell_Newman

Is the current owner one of his heirs or some other party?

These are off-prints of published papers, not his original notes - so why don't I just go top the library stacks and photocopy the original journal ?

"The papers are thought to be of particular historical value as much of Turing's war-time work was destroyed under the Official Secrets Act and the man himself kept few personal possessions."

Yes - thats the point, all the interesting stuff - the notes on enigma and the invention of the computer are gone. All we have are a bunch of preprints from the 30s - but these are preprints of journals that do exist

(note to those under 50 : upto to the 1980s journals would send you a few dozen unbound copies of your paper for you to distribute - before photocopiers were common)