| Reference Number | TPC/5/7/62 |
| Title | Diagram of Patchboard Show Numbers |
| Level | File |
| Date | 07 February 1974-15 March 1974 |
| Description | Evershed Power-Optics Ltd drawing number X12617, unnumbered issues and issuc C. |
| Extent | 3 drawings |
| Series | Evershed Power-Optics Ltd Drawings |