Hi Pauline,

If the photograph was paid for, that is Joe or Josephine public walked into a studio, got their photo taken and paid for the proceedings and the photo print (and negative, although the photographer usually retained the negative). then contract law applies.
The photo was then said to be commissioned.
Copyright in Commissioned photographs taken before 1st August 1989 belongs to the commissioner, not the creator provided money was paid for the photography.
Contract Law over-rides Copyright Law.
Duration of copyright in photographs is complicated as the law changed in the acts of 1956, 1988 and 1995
Generally if the photographer is unknown then the 70 years from the date the photo was taken applies, wether published or unpublished.
If it's a Crown or Parliamentary photo different rules apply.
Run your photo through Tineye or the Google image search. Others are in Beta at the moment.
George