The museum plans to have the "Portrait of Dirck van Os" placed in its Hitchcock Gallery for public viewing on Tuesday after an absence of around 15 years. It's been restored and embellishments added by others have been removed.
Rembrandt experts have examined the painting and certified it as an original work by the 17th-century Dutch master. The museum has not provided a monetary value for the painting, but Rembrandts have sold in the tens of millions of dollars in recent years.
The "Portrait of Dirck van Os" was bought from a private collection in 1942 but was reclassified 45 years later as a painting by one of the students in the "School of Rembrandt." It remained on a Joslyn wall until December 1999, when it was taken down and stored.
The Omaha World-Herald has reported that the painting might still be in storage were it not for a visit and viewing in 2010 by Dutch art historian Ernst van de Wetering, the man behind the Rembrandt Research Project.
In March 2012 it was sent to Amsterdam for further analysis and conservation. Van de Wetering worked with Martin Bijl, former head of restoration at the Rijksmuseum in Amsterdam, to bring the painting as close as possible to its original condition. The museum said that later additions to the subject's clothing were retouched with paint of the same color as the original background. Old damage and missing areas on the painting's surface were retouched under magnification, using what remained of the original paint as a guide.