Museum of the American Revolution shows off rediscovered musket made in 1770s

PHILADELPHIA (CBS) — As Philadelphia gets ready to celebrate America's birthday, a museum in Old City is welcoming a rediscovered musket that was used during the American Revolutionary War.

Monday was a day for celebration at the Museum of the American Revolution as staff debuted a long-lost Revolutionary War musket.

"The assumption was that these things were long gone and would never be seen again," museum CEO Scott Stephenson said.

Historians showed off the .78-caliber musket and its 45-inch barrel while wearing white gloves. It will be on display soon.

Because of the engraving on the weapon's brass plate, experts think it was made in New England in the early 1770s and used by the militia in Providence.

Historians think only 3 or 4 of these types of muskets have been discovered so far.

"We don't know how many of them were made for the town of Providence, Rhode Island, possibly 100," historic arms expert Joel Bohy said.

In 1968 the long gun and other artifacts were stolen from the Valley Forge Historical Society.

In 2003, the museum acquired the remaining collection of artifacts.

Local police and the FBI then opened an investigation for the stolen relics.

Finally, in April of this year, a major break in the case came after Bohy was at an antique arms show.

"I got excited about it, took some photographs," Bohy said. "And then about three weeks later I received a press release with the rest of the missing arms that had been taken in the 60s and 70s. And the first gun on that list was a Providence militia musket."

Bohy contacted police and they were able to recover the musket.

"The rest is history," Bohy said. "They were able to get it back."

It's a rediscovered piece of history that's coming just before Independence Day .

According to the Montgomery County District Attorney's Office, this is just one of the items that was stolen during the 1968 incident. They're still on the lookout for 31 other artifacts from the American Revolution.

"Either this year or next year is the 250th anniversary of that gun being built," Bohy said. "It's pretty heartwarming that it's actually coming back and that people will be able to come and see it."