Aside from guys like the legendary Moe Dalitz who parlayed their careers into casino ownership, or the Lansky brothers who did the same thing, I was thinking more along the lines of individual gamblers who ran separate gambling operations.

A 'Jimmy Nap' Napoli falls into this category because he ran a huge numbers business, etc.

For my money, one of the most unique guys I have run across in my studies was a fellow named Joseph Mastronardo, aka "Joe Vito"

Not a mob-connected gambler per se, or a otherwise street savvy hoodlum who dealt in other rackets as well, Joe Vito was a martian from space dropped into the gambling underworld who was revolutionary in his methods.

I just posted up his biography if anyone cares to read it.