I had overlooked the death of Thomas McQuade (due to searching up until 1883 instead of 1893!) Thank you for bringing it to my attention Gadget. As James McQuade married in September 1893 it would seem a possible link.
However, I still have been unable to find a birth of a James where Thomas is the father. Interestingly, I have found that Thomas & Jane (above & of St Giles) had a son Edward in 1859 that I can find no other record of. I am still searching to see if I can find him with his grandmother or aunts in Leith!
Thank you MonicaLesl, for finding the Stockton McQuade family. I finally ruled them out after finding the 1871 (recorded as McQuide) gave the father's name as John.
Thank you once again for your help.
Charlotte