(WHTM) - The FBI and other law enforcement agencies are searching for Revolutionary War-era firearms that were stolen nearly five decades ago. Since 2009, law enforcement has been looking for memorabilia that was stolen in and around Valley Forge Park in Pennsylvania in the 1960s and 1970s. Three men who admitted to taking the items have helped investigators, however not every piece of history has been recovered. Multiple firearms were recovered this year, including a musket that was returned to a Philadelphia museum earlier this month. Officials provided a list and description of items collectors should keep an eye out for. John James Audubon's shotgun This 12-or 16-gauge double-hammer, double-barreled shotgun once belonged to John James Audubon.  The gun was stolen from the Academy of Natural Sciences of Drexel University in March 1972.  It may have been sold at auction after the year 2000.  The gun is 4.5 feet long.  Smaller Schimmel eagle This carving was created by Wilhem Schimmel.  This item was stolen from the York County Historical Society in Pennsylvania in January 1979.   It may have later been sold at auction after April 1998.  The carving has a 10-inch wingspan and stands 6.5 inches tall.   It’s painted brown with white and black spots.  The item is missing a small piece of wood on its cross-hatched head feathers. Larger Schimmel eagle This carving was created by Wilhem Schimmel.  This item was stolen from the Reading Public Museum in Reading, Pennsylvania, in February 1979.  It may have been sold at auction after April 1998.  The carving has a wingspan of 17 inches and stands 9.5 inches tall.  It’s painted black and has a cross-hatched carved body. It also has a green base and pastel yellow and orange paint over its wings.  The item is missing wood on the tip of its head and feathers.  Carved powder horn dated 1776 with deer and Native American scene This powder horn was stolen from the Old Stone Fort Museum in Schoharie, New York, in June 1971.  It’s golden colored, about 13.5 inches long, and has a flat pine butt.  The powder horn features a “CDM” monogram and “1776” above the drawing of a snake and the initials “JW” above a drawing of a buck with antlers.   1690 English oak Bible box This box was stolen from the Haverford Township Historical Society in Pennsylvania on April 14, 1979.  The Bible box is made of oak wood.  The date “1690” is carved on its front panel.   Leads in the case have stretched as far as San Francisco. "We were all committed to seeing justice—not just bringing the objects back home, but seeking a proper prosecution of those who perpetrated these crimes," said Special Agent Jake Archer, a member of the FBI’s Art Crime Team who worked this case for FBI Philadelphia.  “With the 250th anniversary of the American Revolution coming up,” said James Taub, an associate curator at the museum, “the teamwork and partnership between local police and the FBI have given us in Philadelphia and the historical community at large a really strong opportunity to reach people in ways that we haven't before, through objects that people of my generation haven't seen and that previous generations might not have seen since before the 200th anniversary of the American Revolution.”  If you recognize any of the items, you should contact the FBI by calling 1-800-CALL-FBI (1-800-225-5324) or by visiting tips.fbi.gov. You can submit tips anonymously.