So-called Midcentury Modern bookends were produced from about 1950 through 1980. Those from the1950s can be identified because they were very curvaceous and frequently lacked sharp angles entirely. See our August, 2013 post on Mid-Century Bookends. The Shovel bookends shown above are probably post 1950s, perhaps from the 1960s. A JenFred Desk set with similar bookends can be viewed at the website A Ben Seibel Design.
Shovel Bookends by Ben Seibel