Thanks tvelinsk, I've called my father and passed on your advice and that's put his mind at ease. His guidebook has the Mandarin characters for all the major cities so he should be able to recognise Shanghai on the board when he gets the return train.

Also, thanks Skillet for the hotel recommendation. Unfortunately he can't fly into NKG as he's travelling on a Qantas Frequent Flyer award flight from Sydney to Shanghai. That's the reason he's going to do the side trip to Nanjing as I could only get a SYD-PVG J seat 6 days before the organised tour starts, so he's got a bit of extra time. I managed to get a PKG-SYD J seat for the day after the tour finishes in Beijing, so he doesn't have to wait around there.