As former Olympic swimmer Gary Hall Jr. continues to rebuild from the devastating L.A. wildfires, he can now cross replacing his 10 Olympic medals lost in the tragedy off his list -- as the IOC presented him with replica medals during a private ceremony Monday morning.

Hall Jr. made the trip to the International Olympic Committee headquarters in Switzerland for the event ... four months after he lost his Pacific Palisades pad to the blaze.

It was an unprecedented gesture ... something Hall did not take lightly.

"Thank you for the medals," Hall said. "Never before have 10 Olympic medals been replaced. Probably because no one has lost 10 medals before. I will do a better job at taking care of these."

He lost his medals from the 1996, 2000 and 2004 Olympics ... and detailed the harrowing moments of escaping the fires with Harvey and Charles on "TMZ Live" in January, saying he had "probably tops three minutes" to gather what he could.

Thomas Bach, president of the IOC, said the 50-year-old overcame the tragedy "in the style of a true Olympic champion."

"I cannot tell you how much we admire you," he said. "Not only because of the medals, but because when we were reading your tragic story of losing your house, your possessions and all your worldly properties, this went straight to our heart."