I don't know about any others, but I have found so far the Key that came with my LOTRings must be a master key, It has opened all the machine with that style lock, very weird.
I just wondered if all the keys I got would work in the machines that I didn't get keys for. So I played put & try.
LOTRings opened them all. Be nice if I can get it dupped, we would all have keys than.