Need help with a lock salvaged from a historic psychiatric facility (~1870s) in the United States. I believe the lock to be Mallory & Wheeler brand, though it has no markings. It looks like the locking pin has been either removed or snapped off ( Pic 3 ) and lever 2 has two notch cuts. It looks like the lock either accepted two different keys, or the key was assymetrical, however when in the unlocked position the lever notch ( lever 2 ) would be engaged in the locking pin and appears that it would only allow the key that unlocked it to be capable of re-locking. I provided 3 possible renderings of the key.

Can anyone provide any insight with this lock?
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