In 1976 it was still necessary to leave the train when entering China. You had to walk across the bridge and to enter another train (see e.g. text on the 1980 Hong Kong map http://gwulo.com/atom/20544).
Actually, when we crossed the border in August 1980, we didn't have to leave the train. I do not have any photo of that because it was strictly forbidden to take photos. <Read more ...>
Date picture taken (to nearest decade for older photos):
