Nice watch.
Your grandfather had a nice peace.
Baume et Mercier was the fuel for me to take the journey into watches.
Recent bought 
my first au750 BM.
Family brand, my brother had a kind of watch of your grandfather.
I cared for that watch, soon i never saw it again.
While i know my brother have a weak spot for Jaeger LeCoultre, i hope he find one.
I will give him a memovox, if i do not keep it for myself of course 😉