Found another piece of the mystery. Dad had remember the name of his street as “Nagala lu”. Well, we found it by going to the a police station and was told there are only two elementary schools in this area so a quick walk and we found it.
Nagala is really Dan Shui Lu between Xingan Lu and Taicang Lu. Just blocks from Xintiandi. And the real french name is Rue Chapsal and it was between Rue Marcel Tillot and Rue Auguste Boppe. Chapsal looks like he is http://en.wikipedia.org/wiki/Charles_Pierre_Chapsal who is a French grammarian. August Boppe looks like a French author and artist and also consul to the Orient.