Marina’s had control of his tax returns and I think made some available to the public. He was only 24 when he died. Yes, I think they have a good trail of his employment as well in New Orleans and the Dallas Fort Worth area.
One of the things that disillusioned him was when he went to the Soviet Union, he thought he'd get some cushy postion.
Instead, he was given some boring job in the middle of nowhere.
When he returned to the States, he then turned to Cuba as his Marxist "paradise".
He thought the Soviets weren't doing Marxism "correctly", but somehow Castro was.
He wasn't paid much, EVER.
He and Marina lived in a dump.
All he had to his name when he died was some paltry amount of money and his guns.
He left some $ for his family, in addition to his wedding ring.
Marina left him, and he had nothing left to lose, especially after Cuba refused his passport request.
If he was ever "paid off" by conspirators, he never showed evidence of it.