Did I read the dates incorrectly on your journal? I thought your James Muir and Mary Whyte were much earlier than mine

I have parents of James Muir (Baptism 27 January 1750/51 Inchinnan,Renfrew,Scotland) as Alexander Muir and Janet Paterson - married 25 Jul 1742 Inchinnan.
Siblings Matthew 1745, Janet 1748, Mary 1752, Martha 1754.
(No further back - I think there were too many Alexanders

)
Parents of Mary Whyte (1756) - Thomas Whyte and Elizabeth Blackwood - married 28 August 1740, Erskine. siblings of Mary - James 1741, William 1744, James 1745, Elizabeth 1748, Janet 1750, John 1753
Parents of Elizabeth Blackwood (1719) were John Blackwood and Janet Petterson married 26 Dec 1718 Erskine. Have found no siblings.
Trish