I am 99% sure that the 'Leon' in the Sylvia Odio story was an Oswald lookalike and provocateur. I think I probably accepted that after reading the Joachim Joesten books.
I suspect that Lifton's 'Final Charade' will argue that Oswald was given a fake intelligence assignment to 'lure out' potential anti-Kennedy malcontents by saying provocative things such as the statements by 'Leon', but I don't know what sort of evidence he has. I have always regarded the Sylvia Odio story as being one of the 'framing Oswald by lookalike' episodes.
I like it when there are multiple pointers to the truth. And in this case, we have no reason to believe that the Oswald of fame was in Dallas at the time. He was supposed to be in Mexico City. He wasn't there, but he wasn't in Dallas either. If he was in Dallas, he would have contacted his family, and he didn't.
But, the whole story stinks out loud. You had the guy saying "Leon" was an expert marksman. Well, that certainly wasn't true of Oswald. He owned no rifle. He did no shooting since he got out of the Marines except for rabbit hunting with a shotgun in Russia, and his Russian pals said he stunk at it- and even David Lifton has admitted that. I've heard him say it.
But, the worst thing is the claim that Oswald said that "You Cubans should have shot Kennedy when you had the chance..you didn't have the guts." It doesn't even sound like something Oswald would say. When was he ever flippant about shooting someone? And, there is absolutely no doubt that he liked Kennedy. Even his wife, who betrayed him so badly to the WC and portrayed him as a deranged monster, was unable to conjure up the thought that he disliked and disparaged Kennedy.
So, I rate the chances of that being the Oswald of fame at zero. I don't give it any chance of being true. I know John Armstrong thinks it was "Lee" from his Two Oswalds thesis, which I support.