Fralton is a surname, though fairly rare. May be worth looking to see if you can find a marriage between a MacDonald/McDonald and a Fralton that could have been the reason for his first name.
I also considered how the name may have been mangled by misunderstanding of Scottish accents. This may be a wild goose chase, but in the 1841 census for Peterhead, Aberdeenshire there is a Fulerton MacDonald. He is 60 at the time, but it could be worth looking at his grandchildren to see if one could have been your Fralton.