Engraving is the practice of incising a design onto a hard, usually flat surface by cutting grooves into it with a burin. The result may be a decorated object in itself, as when silver, gold, steel, or glass are engraved, or may provide an intaglio printing plate, of copper or another metal, for printing images on paper as prints or illustrations; these images are also called "engravings". Engraving is one of the oldest and most important techniques in printmaking.
I looked at the pictures closer and looks printed on to the metal not engraved... but was printed on that metal with a engraving plate...also looks to be the same image as used on the old 5$ bill...
That's just a metal print. It wasn't printed with an engraving plate. Those are just details from the photo used to create the print. Depending on the age it could of been printed several ways. Those type of prints usually run about $25 to $50 new.