Sellers says Lock maker only. I suppose meaning he didn't make guns. But says nothing regarding being a lock importer.
I don't know if you realize that there were literally hundreds if not thousands of lock makers in this country, and true, some imported locks and marked them with their name. Probably no way to know for sure, but I'd bet they had no qualms copying some other makers work.
I have about 40/50 original flint and percussion lock plates; none have the same name on them, and none are exactly the same size.
John