Thanks for all the info. We are still operating the plane under N-registration. In not too long this will be changed to a B-registration, making it necessary to take the written test.
I had an interesting meeting in Beijing with one of the CAAC examiners being responsible for the written tests. He told me that if there is a question that doesnt make sense (wrong translation), it is possible to mark it and the CAAC will review the question. According to this examiner, the CAAC will even correct your score if it was their mistake.
Regulations wise, so far I havent been able to find an English version of the FAR's. Part 61 is in English. Part 91 and the rest is only available in Chinese. Part 91 is very much the same to FAA Part 91. A difference is that they used the metric system.
Will keep you informed about the written test.
Sander