Or...having a roulette wheel in the picture, regardless of what's in his hand, might have been artistic license? According to Wiki, the movie is a slot machine based drama... And if the wheel is artistic license, the object in his hand could be artistic license?
"King of Gamblers is a 1937 American low-budget gangster film directed by Robert Florey. Akim Tamiroff takes an unusual featured role as a slot-machine racketeer whose bombing of an uncooperative barber shop leads to a murder charge. (The film was also known as Czar of the Slot Machines.)"
There's a trailer available online, or maybe the whole movie, but I'm not downloading the program to play it.
Just another possibility...