It seems to me authorities should ideally be uploading such files to their websites in order to make the information as accessible as possible. The files would contain "environmental information" and would therefore be covered by the Environmental Information Regulations 2004. The Regulations require authorities to make such information available if requested and people can ask for the information to be supplied in a certain format (e.g. electronically). Uploading the files would obviously mean people wouldn't have to request it. All local authorities will have their own "Publication Scheme" under the Freedom of Information Act 2000, which sets out the information the authority routinely makes available and how people can access it. Any arrangement concerning historic files should therefore comply with that scheme. There's more information about the Regulations on the Information Commissioner's website: http://www.ico.gov.uk/for_organisations/environmental_information.aspx
