Gabe Dowrick sent me this reply about the film:
"The Swallow was made as part of an art project and has not / will not be publicly screened. Tabrett only had a small role in a single scene. We shot in 2007, I think."
Sad to know we won't see the whole thing but at least we won't have to keep guessing what's going on with this project. Maybe this was a part of her training, she was at Screenwise in 2007.
Either way, thanks again for letting me know, Gabe!