I have spent this evening searching 'Scots Origins' records website and it would appear that my grandfather was indeed your uncle Hugh. My grandfather was born in East Kilpatrick (where your parents grandparents were married - in 1884?). My grandfather Hugh was born in 1885.
That would make you my grandfathers niece, my mothers cousin and my 2nd cousin? Would you agree?
Where do you live? I live in Bishopbriggs, a suburb of Glasgow.