The name "Paratrooper" was not a model name used by Norinco. It was not a marketing scheme by Norinco either. In the late 1980's Navy Arms imported several versions of the SKS rifle. They gave the different models thier names. They used the name "Paratrooper" to distingish the SKS rifles with 16" barrels from the standand SKS rifles that had 20" barrels in their advertising. After the Navy Arms ads came out touting the "Paratrooper" model SKS all the wholesalers started using the name in there advertising too.
Navy Arms gave model names to several other versions of the Chinese SKS rifles they imported that had 16" or 20" barrels with factory installed features such as scope mounts,5rd mags, and bipods. Their names were the Cowboys Companion,Ranchers Friend,Hunters Companion,and Hunters Friend.