Chain guard and stem don't look Schwinn. It'll be hard to find the model without the original chain guard. It can be narrowed down, what's the serial #?
That chainguard is unique to 24" Schwinns. It looks to be a 1954-58 bike, and most likely a Corvette. The Tiger models were generally all 3 speeds, and the Americans also had a checkered seat tube decal. Date it by the serial, and you can check against the brochures for that year online. -Adam