Hi Reg
Thank you for your reply, and I believe there is actually something I could share on the manufacturer of both the IC parts and PCB/boards/Modules.
RoHS was brought to the market somewhere around 2006 if I am not too old to remember. Somewhere around that, China didn't have much tech-abilities. The level of Chinese technology is low, you can compare with the SEA countries especially Vietnam today, China's role in the world market was to be the factory, and that's when the industry thrived.
But the problem is we had no high-level science knowledge and what we could do is get the data from US and EU and produce the product without knowing what is it.
This caused 2 things:
1. You can find almost any old parts or datasheet/design in China.
2. There is too many fakes.
And since today, on the IC field we have not a big brand, but focus on so called"Chinese alternative/replacement".
For your question, you could easily do a little search on Alibaba, and contact those stores sell RF borad, I believe they could cooperate much smoother than me cause my field in on IC

Hope this is helpful!