Found these on the 1871 Census, don't know if its any help.

RG10/786/101/35 Transcribed as Mc Affrey but reads Mc Caffrey
Army Service Corps Barracks and Royal Military Academy, Woolwich
JOHN MC CAFFREY 33 Sergeant Royal Artillery b St. John, Newfoundland
Rose wife 23 b Canada
Frederick Kemsley brother in law 14 b Woolwich, Kent
Also living at the same place in 1871 RG10/786/34
John Ferguson 64 Gate Porter at R.M.A Chelsea Pensioner b Scotland
MARY Ferguson 50 Chelsea Pensioners wife b Ireland.