Sheepbridge Coal and Iron Co Ltd, Chesterfield: Unlisted records Unlisted accession, Apr 2011 (previously D7422): Iron ore analyses, with financial papers, late 19th century Unlisted accession, Aug 2016 (previously D7992): Title deeds, including mineral leases, associated bonds and mortgages, copy wills; photographs, 17th-19th century (6 boxes)