Yeah, amazing what's not easy to find.

I recently found out about the ancient roads in China. These days they are hiking paths. I'm quite used to handling myself alone with a GPS track, I don't want a guide. I found one book that it's not remotely clear if it's got what I want as it's discussing much of China and it's old enough I'm not sure what the mapping info will be like.

You'd probably be better off not trying to navigate using GPS in China in the first place, given the whole mapping situation there.