Like you I am descended from the James/Hugh Boyce family. My ggg grandfather was Hugh Boyce married to Jane Murray. I found you messages very interesting and totally agree with your 'guess we will never know - intriguing' statement in relation to James/Hugh's parentage.
I have also found a mystery and thought I would pass it on to you to see if you have any clues. Hugh & Jane Boyce had a daughter with the middle names of Aitken Anderson.
Hugh & Jane Boyce had 10 children and they are as follows
Thomas Boyce born May 1850 in Dalry Ayrshire, so Hugh and Jane must have arrived in Scotland between there wedding in November 1849 and his birth. Thomas is presumably named after Jane's father.
James Boyce 1855
Robert Boyce 1856
Hugh Boyce 1858 - presumably after his father
Mary Boyce 1860 - presumably after Jane's mother
James Boyce 1862
Jane Boyce 1863 - presumably after Jane
Elizabeth Boyce 1866 - presumably after Hugh's mother
Here is the interesting one
Margaret Aitken Anderson Boyce 1869
Annie Boyce 1872
Where did Aitken and Anderson originate ?