Tarilan,

the novel "Falcon and Wolf" was a novel with was not published in bookform. This is the reason it appeared on the WoC web. All other Birtright books made it in print format, so I guess they will not be published on the web.

Take a look at the "Shadow Stone" from Rich Baker, which is actually a Forgotten Realms novel and currently available via Amazon. It was previously written for the Birthright settting and changed in the last minute to FR (because the BR product line was cancelled).