Safety deposit boxes.

I believe they came from Cleaver House - a sanitorium on The Wirral that closed shortly before my house was converted from farm buildings. I just can find photo evidence.

I believe double keyhole locks like this were frequently used in buildings that had a master key. I've seen many antique doors (mostly entry) with double keyholes like this. One hole is for one specific key that can only open this door, and the other is the same on all doors and can be opened by the master key.

That would make sense for a sanitarium because they'd want to restrict certain staff members' access to certain rooms.

I believe the building had many phases and uses over its lifetime.