Air Aces of the 1914-1918 War has him listed as being born in Aldershot, Oughton's Ace With One Eye gives it as Preston Cavalry Barracks, Brighton,
Taffy Jones' Tiger Squadron says Cork while (I believe) Jim Dudgeon's book carried a copy of Mannock's "ticket" that had Cork written on it. I must get myself a copy the book to keep - I'm getting tired traipsing up to the local library only to find their sole copy is on extended loan!
Graeme