Long lost Cherry Hill Rockwell is back, but one mystery remains: Who stole it?

A Norman Rockwell painting stolen from a Cherry Hill home in 1976 and recovered by the FBI's Philadelphia office last year was officially turned over to the deceased owner's children Friday.

The Center City ceremony marked a happy conclusion to a tale that began with a game of pool,  took a fortuitous turn after a chance conversation on a golf course, and likely would not have ended so well without a retired FBI agent who had a hunch and a Rockwell admirer's husband who did the right thing.

"Today's a great day," said Michael Harpster, special agent in charge of the Philadelphia FBI office, starting an event that celebrated the fine collaborative work of his and other enforcement agencies, as well as the reunion of Ocean City resident John Grant  and other family members with a fondly remembered heirloom.

"We never thought this day would arrive," Grant's wife, Marybeth, told the crowd in an FBI conference room, where the framed canvas was displayed on an easel.

"We waited over 40 years to be reunited with this very special painting."

Variously known as Lazybones, Boy Asleep With a Hoe, and Taking a Break, the 25-by-28-inch, quintessentially Rockwellian canvas depicts a young farmer snoozing against a tree with his sleepy dog.

The painting was reproduced on the Sept. 6, 1919, cover of the Saturday Evening Post and hung in the foyer of Robert and Teresa Grant's home in Cherry Hill's Fox Hollow section for 20 years before it was taken during a June 30, 1976, break-in.

"My father really loved that painting and always thought it would be recovered," said Susan Murta, one of his daughters, who's 58 and lives in West Chester.

"It's unbelievable," said Liz Schleinkofen, now of Philadelphia, who last saw the painting hanging in the family's Cherry Hill home. It "looks better" than she had remembered, she said.

John Grant, 56, said his father paid $50 for the painting. Robert Grant accidentally damaged Lazybones with a pool cue during a 1954 game at the Haddonfield home of a friend who owned several Rockwells and was pals with billiards champ Willie Mosconi.

The thumbnail-size puncture in the canvas is still visible and proved useful in the case, investigators said.

Not long after the 1976 theft, a Philadelphia-area antiques store owner paid several hundred dollars for the canvas, and the Grant family received a $15,000 insurance settlement for its loss.

The painting is now valued at more than $1 million, family members said.

While modest in size and muted in color, the canvas has the humor, rich details, and other traits "that made Rockwell's work so popular," said Martin Mahoney, director of curatorial operations at the Norman Rockwell Museum in Stockbridge, Mass., which along with the Barnes Foundation in Philadelphia offered assistance in the recovery effort.

Rockwell's work "is special to Americans," noted Timothy Carpenter, supervisory special agent with the art theft program at FBI headquarters in Washington, who attended the ceremony.

John Grant's interest in solving the disappearance was revived in 2006 when he discovered a folder of information about the canvas that had belonged to his father, Marybeth Grant said.

But a conversation John Grant had with a friend, retired Cape May County chief of detectives Jim Rybicki, at the Atlantic City Country Club in the summer of 2011 proved crucial. "I said, 'You ought to talk to Bob Bazin,' " recalled Rybicki, who lives in Ocean City.

A retired Philadelphia FBI agent instrumental in the 1989 recovery of a sculpture stolen at gunpoint from Philadelphia's Rodin Museum, Bazin was intrigued when he heard from Grant.

The fact that the Rockwell seemed to have vanished without a trace suggested it was still "somewhere on a wall" in the Philadelphia area, he said.

Bazin, who lives in Cherry Hill, also believed that media attention could be useful; he said a 2011 report by a Philadelphia TV station and my 2013 column helped renew interest in the case.

And last year, an FBI news release pegged to the 40th anniversary of the theft led to the flurry of coverage that apparently caught the attention of the antique shop owner.

Investigators said the man wishes to remain anonymous and is not facing any charges in connection with the painting, which he was unaware had been stolen and in any case believed to be a copy -- and a damaged one, at that.

But he held on to Lazybones for 40 years because his wife liked Rockwell, investigators said.

"He thought he had a copy hanging in his kitchen," said Louis D. Lappen, acting U.S. attorney for the Eastern District of Pennsylvania.

He called the man "a good citizen" who enabled the painting to be returned to its rightful owner.

But it turns out the story may not be over just yet.

John Grant said he and his five siblings have yet to decide what should be done with Lazybones, which will be kept in secure storage until they do.

Jake Archer, who along with Don Aspler was co-agent on the case, said the FBI has put together a description of a potential suspect in the original theft.

But he declined to comment further.

Said Lappen: "It's still an ongoing investigation."