How can I find out if any Navy Crosses were awarded for actions in the 1983 Beirut bombing?

In 2015 while at a church function with my grandfather, I was introduced to a man I'll call Mr. X, who served in the Marines 1981-1991. As a young LCpl, he had been with 8th Marines in Beirut in 1983. A family friend and former Marine Cpl named Dave told me that Mr. X had been awarded the Navy Cross for actions in Beirut on the day of the barracks bombing that ultimately killed 241 US Marines. When I pressed for details out of curiosity, Dave told me Mr. X didn't like to talk about it.
Mr. X is very involved in veterans' organizations where I live. He's also a Patriot Rider. Over the next few years I would come to know him as quiet, humble, and friendly. At one point he told me a little of his story surrounding the Navy Cross, how he was on a foot patrol with his squad when they heard the blast and saw the smoke where the Marine Barracks had been. He told me the squad made their way back to the barracks in a running gun battle, and it sounded like he had saved a few lives in the process.
One day in 2019 I was doing research online for valor awards and found a page that showed Service Cross and MOH recipients from all US conflicts. I was seeing Silver Stars and Navy Crosses in Panama, MOHs in Vietnam and Somalia, and plenty of everything from both World Wars, but one conflict I didn't see was Lebanon. I started researching on the Internet about awards and I failed to find any official evidence of a Navy Cross being awarded in Lebanon. Mr. X's name matched his FB profile in a Google search but showed nothing else. I read through news stories of the Oct 23, 1983 bombing and found one article that stated several Bronze and Silver Stars were under consideration for troops who were there, but nothing of the second-highest Valor award being awarded to a Marine LCpl. Since then I've tried looking it up and surreptotiously reaching out on a few FB pages to see if Mr. X is telling the truth, to no avail. I haven't made a request through the National Archives for his service record and have hit a brick wall when speaking with older Marine vets who know him. Dave even told me when I pulled him aside, "You know, I thought the same thing when I first met him, I did research and asked around and couldn't find anything ... but now it doesn't bother me. We're all good Catholics and I wouldn't hold it against him if he were lying ... and besides, sometimes awards are classified, maybe he was doing secret stuff when he got it". I have a hard time trying to figure out what a LCpl in a rifle platoon would be doing that warrants such activity. I got the impression that nobody wanted to even consider this good man could be lying.

Were any Navy Crosses awarded in Lebanon? How could I find this information?