Not knowing your grandfahters maiden name there are several Jones listed in the 1921 census in the town of Whitmourne (http://ngb.chebucto.org/C1921/M8040/804001.shtml). The 1921 census appears to be the largest of the searchable database on the site. The versity of orgin of the people listed might have ment there was a great draw to the area at the time. ....Maybe mining. I've never researched this area before though have a few relative that moved there.