I still maintain it's something metal or at least sturdy, to create that noise. Especially the last part, it sounds like a hinge to me, one that is dropped and settles. The first part sounds like a latch or something simple and mechanical. The middle noise is the most difficult for me to identify, I can't entirely place my finger on it. Sorry I can't help more than that, folks.
Best of luck, Asmodeus and Tegan.