It's a Schwinn frame and forks. I agree, looks like a 24" bike. Not original fenders, and it definitely been repainted and striped, the headset bearing cups are painted over. Luckily the nice head badge looks untouched. The homemade striping also isn't like anything Schwinn did. It has a skiptooth wheel and chain with a standard Schwinn chain wheel. The wheels don't look Schwinn either. Not a Schwinn chain guard either, but it looks like a good bike. The serial number, either on the bottom bracket or left rear dropout will let you know the year, and from there you can guess which model it may have been. Being a straight bar frame, I'd guess 50's, but the serial will give the date of manufacture.