The NC-50 is a Honda Express. The oil tank and gas tank is located inside the rear rack. They are in the same body.
Mike, I'd recommend that you take the tank out of the rack and fill up one side with gas. See if it leaks on to the other side. If not, then somebody probably made the mistake of putting gas in the oil tank. That's not good news, because it's possible that the Express was run without lubrication for a while and might have soft-siezed before if it actually turns over.
If the tank indeed leaks, I'd forget about Kreem. Just get a new tank. It'd be easier. In the meantime, you could disable the oil injector and premix oil and gas in the tank until you get a new tank. Then when you get a new tank, enable the oil injector and hook it up. Just a suggestion.
I owned a NA-50, which is a Honda Express II. These scooters are fantastic! I miss my old one. It ran beautifully.