Ian, it looks to be quite straightforward to obtain a digital image from them although prices are on application if you want more than 300dpi.
http://www.cegesoma.be/cms/banque_img_en.php
These scans are from period copies of German propaganda images so the quality of the original may not be great - but better than on-line.
If you want to order, send me a personal message and I'll try to tell you where to find the pictures. It doesn't seem to be possible to hyperlink to search results and it's always searching within a search to find anything.
Rich