This shop keeps only genuine articles.

Genuine : truly what something is said to be; authentic.
Imported : (of goods or services) brought into a country from abroad for sale.
Spurious : not being what it purports to be; false or fake.
Antique : a collectable object such as a piece of furniture or work of art that has a high value because of its age and quality.
Duplicate : exactly like something else, especially through having been copied.

Antonym of Genuine is Spurious