Antique Union Shield Escutcheon Plate (for Door Latch)

I'm finding myself drawn to antique emblems of America of late, I think clinging to an optimistic idea of America that seems to rapidly slipping away.  I know that this antique  shield was made as the escucheon for a door latch. (Now, seems like a good thing to hitch the dog leash to!) I find those incised stars (each one slightly different from the next) and hatched lines really beautiful. And a gorgeous patina too. Heavy for its size, I though at first brass but with what looks rust visible in a few spots I think perhaps iron/mixed metal with a brass/bronze-like finish and verdigris.

5 1/4" t x 3 1/2" w x 1 1/4" d and in very good antique condition.