Original Organosol is lacquer and not available in any market I'm aware of anymore. I believe Frank Badalson sells a modern version.
Here is a quote directly from Mopar Connection Magazine regarding Organosol...
The original paint that is commonly called “Organosol” is no longer available. The paint code in the system at a PPG dealer will be listed as DDL 9355. Even if your dealer can still mix the lacquer formula he will not have the original texture additive. He will be able to add texture but the original additive’s particles were larger.
You can also buy DCC 9355. It is a urethane base paint and does not have any texture additive. It also has more sheen than the lacquer paint. Unless you are trying to duplicate the exact original appearance you can use the urethane. The stripes or hood will be smoother and much easier to maintain.
Fortunately I am still in contact with the man who painted my car for it's previous owner in the early 2000's. He recently gave me enough original Organosol to repaint my T/A hood.