For sure, large chunk of those slots, pinball machines, were manufactured in CHicago factories,...
Trust me I know, one of these companies eventually became MIDWAY games, they had a lotta arcade games, I grew up on Mortal KOmbat, even through some people in the know I managed to get autographed copies of phtographs from the game actors, like the guy who played Liu KAng and Raiden I think.... Long time ago now..
But yeah, it's something very overlooked, Hy LArner? Was that his name? I think he had control over the machines, lotta of em went to COstello, Outfit and the Luciano family were always very close...