I'm starting with the low-hanging fruit as I build up the site. There's quite a bit of information freely available on the open web once you track it down; my goal is to get it all into one place. As I do so I'm developing a running list of documentation that's going to be trickier to lay my hands on, in terms of convenience and/or cost.
In particular, there's a great trove of information at the League of Nations archive in Geneva. Their catalog is here if you'd like to see for yourself. Their access policy allows registered users to view their LON files but prohibits photocopying. It makes sense, considering many of these papers are getting on in years. I'm surprised, though, that they haven't got a book scanner that could do the job without damaging the documents. It's worth looking into at a future date, as there's simply too much information kept there that isn't reflected in the Official Journal entries. The story of the Free City wouldn't be complete without it.