TONAWANDA, New York-Martin Kober is convinced the painting of a dying Jesus that hung above the mantel in his childhood home is the work of Michelangelo. Getting experts to agree remains the $300 million hurdle.

That's the potential value of the 48-by-64-centimeter work that Kober's family affectionately calls "The Mike", a one-time living room fixture that occasionally got dinged by a thrown tennis ball and once fell from the wall while being dusted.

Kober has for the last 15 years taken his Michelangelo suspicions to the art world and gotten a mixed bag of scholarly opinions. For now, the circa 1545 family heirloom that was given to Kober's great-great-grandfather's sister-in-law by a German baroness remains in an out-of-state vault while he seeks the elusive validation.

"It's tormenting now," said Kober, a retired commercial pilot. "I'm nobody, I'm not connected. I don't know if that's it."

The painting depicts Jesus supported by two angels in the lap of the Virgin Mary. Doubters view it as not good enough to be by Michelangelo or believe it's another artist's version of a much-copied Michelangelo drawing. Some claim that the then-70-year-old artist would been too busy painting the Last Judgment fresco at the Sistine Chapel and another fresco at the Pauline Chapel to do another work.

Supporters of Kober's claim cite written historical references and forensic evidence that includes Michelangelo's preferred paint type, small brush strokes and mid-work changes visible by infrared testing that they say indicate an original, rather than copied, work.

"Unfortunately, the world of attribution is never a definitive affair," said Michelangelo expert William Wallace.

Assigning any work to a master is almost always a matter of waxing and waning scholarly opinion, he said.

For now, Kober said he is willing to hand over his quest to an artistic or philanthropic organization with more clout.

"This painting can be poked and prodded all over again if that's what it takes, but the results will be the same," he said. "It's a Michelangelo!"

Associated Press