Regarding to Dan Lurie he created/registered "International Federation of Bodybuilders' before J.Weider organized his International Federation of Bodybuilding !.
They use to be business partners ?.
Lurie palled around with Weider post WWII. Lurie advertised his stuff and used Weider's magazines to fight with John Grimek, Bob Hoffman, and York Barbell. Lurie had a fight going with Grimek and York over who was the most muscular man, and Lurie thought he was treated unfairly by York, who was the biggest thing in fitness at the time.
Weider gave Lurie a platform because he wanted to break up York, humble Hoffman, and maybe hire Grimek in the aftermath. Weider once offered Grimek up to $20,000 to be the face of Weider during those years, but Grimek refused, not trusting Weider.
Anyway, who came up with the IFBB first is a bone of contention. Weider and others claim that Joe was talking about starting a new organization up as early as late 1946. Lurie claimed that he registered IFBB in 1947, but he didn't have proof, and used it for the Mr. New York State Contest in 1948. Weider claims his first IFBB event was the Most Perfect Physique and Most Muscular Man Contest held in late 1947.
Edit - Dan Lurie also helped Weider sell and make barbells in the US, that was also part of how they were connected. Dan had the Lurie line and hooked Weider up with foundry help, etc....