How many unaired episodes were left?
Two unaired episodes exist: The last episode of Series 3 and the last episode of Series 4. I personally haven't seen them out in the wild yet.
I think there were 3 episodes unaired.
The 4th from series 3 (s03e04)
and the final two from series 4 (s04e05, s04e06).
The unaired episodes showed up on usenet in the last two weeks.
You can find them with binsearch.info
-Dave
Has anyone spotted locations outside of Usenet? My ISP nuked Usenet access years ago, and I so rarely used it (compared to, say, a decade ago) that it isn't worth paying extra for a dedicated Usenet feed.