You might want to check again about their comment that all records are confidential, since vital records are a matter of public record and should be available to you without being a family member if the record is over 50 years old. I've never ever had a problem getting a death record that is over 50 years old from any county clerk or the state in New York, so I am not sure why the person at City Hall in Dunkirk is telling you that earlier records are not released. You might want to call the county clerk's office and ask about their policy. Does anyone else know if New York has changed their law about releasing vital records?

I believe that Rochester has microfilms of the indexes of vital records for NY (by year)- but I'm not sure exactly where. I think either their public library or university library has them, and you might check LDS.