StrawHat...I saw the story on the news. A clerk in Tombstone was moving boxes, I think it was because they were relocating to another building and she found several old and yellowed, hand written pages in a brown box. Started reading, and whala! A woman witness said that Wyatt Earp had his revolver hidden under his coat while walking to the corral, and when the coat parted some, it opened and she could see he was trying to conceal it by pushing the front of the coat back to a closed position. In the movies he is portrayed as having an open holster.
The news people did not say anything on access, you could contact the City of Tombstone or perhaps the county historical society there. As this must be a big tourist stop, surely they will make the information public.
Public Broadcasting did a recent "American Experience" show on Wyatt Earp. Up until he died in 1929 he was trying to get someone in Hollywood to do a proper movie about him instead of films geared for romance and violence as he was a guy just trying to make a living in a mining town with social cliques. He eventually moved from place to place and died in California, still trying to make a decent living having tried various entrepreneurial activities.