Doug MacQueen wroteLocks of this type are relatively easy to make for a skilled blacksmith. … the basic design is French and goes back to the 15th Century at least. That is not say those locks are anywhere that old. … James Patterson was listed as a lock maker in Pittsburgh in the 1815 directory. Doug
Many Huguenot French/Dutch, and also German Protestant immigrants went to America and made European-style locks, mainly from 17C onwards, centred on Pennsylvania. The simplified style of these suggests later rather than early, so first half of 19C probably about right. Not rare, but not surviving in large numbers.
You would need to ask an American antique dealer if it has any value; indeed, as suggested, try EdDonaldson.
And btw - excellent clear photos, witha scale. Well done and thanks.
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