the CJ750's only come with license plates and relevant documents etc as a sidecar unit, not as a solo. Sure sometimes one can see some bikes where they have the chair removed, but technically thats breaking the law. Also getting 100% legal license plates for the CJ750's for foreign owners (in other words trying to get your name on the motor reg documents) is almost impossible for use in PRC. The sidecars have to be registered in a Chinese company/persons name.
What I suspected, although I was more interested in the someone modding the bike angle. Probably requires Chang Jiang themselves to start to manufacture their own solo and get CCC approval for them to be legal as solos. Clearly there is moderate demand for a solo version for export, and even possibly domestically. The classic bike market is pretty big in some countries. Although Harleys are the obvious modern classic, there are many others which sell well as alternatives such as the Triumph Bonnevilles, Scamblers, the Norton Commando has been brought back from the dead recently. There are even custom bikes using old Honda CB550 and CB750 inline fours these days!