I've experimented with a rather clunky workaround.
I downloaded the "simplified" version available from
here and unzipped it. I ended up with a folder named 030408. I used the file named "index" in that folder as the starting page for iSiloX and set the Depth at 2. The resultant iSilo file was 401kB. It appears to have all the stories and images from the complete paper, though I haven't checked that in detail. Each html page starts off with a series of links, and you have to scroll down to find the text of a particular story. So, as I said, pretty clunky.
Even clunkier is the fact that when you receive the paid for up-to-date zip files, you will have to change the file location every day in iSiloX before you run it - presumably all you need to do is change the folder name to represent the date of the newspaper.
Tomorrow I'll experiment with the other zip - the one with the image de la une et menu déroulant. I imagine I'll have to make sure I don't get the image of Page 1, since it won't be very readable.
Anyone know of a better method? (There must be one!)