The chap in Chicago, whose name is Simeon Peebler, has opted for Mary Arnold. To sum up progress so far, then, we've got Gallows Child and Mrs Dyer already up there, plus these prospects:

Mrs Dyer - RTim (additional version)
The Silent Grove - Suibhne Astray
Streams of Crimson Blood - Artful Codger
Mary Arnold - Simeon Peebler

I've no objection at all to having several versions of a single song up there - in fact, it might be quite interesting to contrast the different approaches. If later contributors want one all to themselves though, they'll have to steer clear of the list above.