Decide how critical it is to put resources into finding out "831 Lost Ones".
Will the idea below work?
Raise money to post ads ( the same date) on TV, chinese newspaper, radios, ...or other mass media to ask for 831 families of injured to contact certain "helpers (e.g. lawyer)" with gaurantee of confidentiality so as to FIND OUT the details and the STATUS !! Encourage them to come forward to tell the truth to Hk people.