How can a 64 yr old male get a work permit in China?

I am 64 years old and only score 65 points out of 80 for an A Grade Work Permit in China. What options are there for our office in Shanghai to get me a work permit? I had tried to get my papers legalized here in the US but they were returned with no action taken, no additional requests for information. I am affiliated with an NGO, the World Association fo Nuclear Operators (WANO) formed after Chernobyl and have a MOU with our equivalent body CNEA in China. While I submit my nuclear experience supports safe and reliable operation of nuclear power plants, that arguement has not been heard. I have a M visa that appears to allow up to 90 days a year in China to do what I can to support. Am I limited to 90 days or is there a way to get a Z visa and work permit?