Hi Halflock. The key was firmly stuck in the lock when we found it. I would have loved to have removed it, but preservation is our main goal and we cannot risk damage to anything we find as it is all just considered on loan to us. Rust removal isn't an option as it has already undergone metal conservation in order to preserve it until we repatriate it at some future date. Thank you!

Thank you Scott! I will look at that website for more information!