I'm on a roll this morning- just spoke to my parents. Your family comes from the same village my aunt Mila has lived in since she married all those years ago and i recall walking to her house from grandads regularly(uphill most of the way!). They spell it Gravsce.
Also, my grandmother (Anda grubisic) was born to Filip Grubisic and Matija Majic. Hope this helps you.