Thanks Lauren for your reply. As someone who has been at this genealogy for 26+ years now I know all too well how spelling is a thing not to spend too much time dwelling on.
My own last name is Moody but its seen spelled every which way you can imagine. In Scotland it was Mudy/Mudye/Muddie/Mudie/Moodie/Moody etc. etc.
So, no I haven't given up on the fact that the name of "Newton" does run in our Ydna Moody family and that it ~Might~ somehow be tied to those of the old town name of Newtownlimavady as a means of them keeping a piece of their old homestead close to them.
I appreciate your input though, and wish you good luck with your Irish family as well.
M.