| Administrative History | These records relate to the Ann Twyford works at Birchover Quarry and the Tom Twyford works at Stanton Moor. The Tom Twyford works are now closed, but the Ann Twyford works have gone through a number of management changes and are now part of Natural Stone Products Ltd. |
| Custodial History | The records were donated to the Record Office in May 1995 |