If no owner claims such article within six months from the receipt thereof by the police department, the police department shall, within two weeks thereafter, notify the finder of such fact by registered or certified mail at his last-known address, and the article or the proceeds thereof shall be turned over to the finder, upon demand by him within thirty days from the expiration of the six months’ period and upon payment or deduction of all proper charges; but, if such finder fails to demand such article or the proceeds thereof or refuses to pay such charges within thirty days from the expiration of the six months’ period, such article or proceeds shall belong to such municipality. The requirement of notification may be omitted when the value or estimated value of the article is less than five dollars.