John Gray born in Maghera Co., Derry about 1826

John Gray born in Maghera Co., Derry about 1826. This information came from a birth record of his third daughter, Marion Gray, who was born in Australian in 1854. John moved to Scotland at some stage as he married Ann Clerk Fisher on 14 July 1850. Falkirk, Stirling, Scotland. They had two children in Falkirk, Scotland, Agness b.19 October 1850 and Jean b.1 October 1852. They migrated to Australia on the Hilton arriving on 10 October 1854. Their third child, Marion, was b. 23 November 1854 Geelong, Vic. They had a further four children. I cannot find any trace of him in Ireland, whose his parents are, any siblings, or when he went to Scotland. All I have is where he was born. Any information would be greatly appreciated or where I would be able to find further information. Many thanks.