I'm Nick Mozak (Motsak) from Belgorod, Russia.
My grandfather Nickolay Petrovich Motsak before the revolution of 1917 lived in a small village near Poltava, Ukraine.
He had five or six brothers, I know only that some of them had names Petr and Gregory.
During the Revolution and Civil War period (1917-1920) my grandfather's brothers moved to the USA and Canada.
Now I know nothing about them.
In the USA and Canada their surname might be changed from Matsak to Mazak, Mozak, Matsuk, Mazuk.
Even here in Russia and Ukraine there are two variant of the same surname: Motsak and Matsak.
So my father was Motsak and his brother was Matsak.
If somebody has any information of such persons or name I'll be very happy to correspond.
You can contact me directly:
Best wishes from Russia