Hi Graeme,
Tailor or Nailer - I don't know! But Tom Corteen, who transcribed the records from the originals, was usually accurate. Perhaps ask the Registry to double-check?
You could also check the 1871 and earlier censuses for John Christian's occupation.
I can't be certain because I don't have these records, but this entry on the IGI looks like Edward's bapt: 31 March 1850, St George, Douglas, Isle Of Man, son of John Christian and Ann. Theirs could be the Maughold marriage between John Christian and Ann Kelly on 1 Apr 1834, but you need some census entries from Douglas to find their ages and parishes of birth.
If you put a message on this list under the subject '1851 - 1871 census lookups please', giving the above bapt date and place for Edward, and his parents names, someone will probably give you these.
Sue