| Present Location | Cholsey Wallingford |
| County Location | Oxfordshire |
| Designed For | BR |
| Built by | Pressed Steel |
| Diagram number | 512 |
| Lot number | 30518 |
| Type | DMBS |
| First Number | 55034 |
| Later Numbers | DB977828 |
| Present Number | W55034 |
| Current Livery | BR multiple unit green livery |
| Gauge | 4ft 8 1/2in |
| Wheel Arrangement | 4-w bogies |
| Original Underframe | Yes |
| Original Bogies/Wheelsets | Yes |
| Additional Notes | Class 121. Departmental stock (Sandite vehicle) 10/92 to 06/96. P 1996 privately for Gloucestershire Warkwickshire Railway, but resold 1997. To Tyseley, where extensively overhauled. Purchased by Chiltern Railways by 10/10 - intended to re-enter mainline service in 2011. To Aylesbury 05/11 - used by Chiltern Railways for Heritage Shuttles service. By 06/15 back at Tyseley. 10/17: to LNWR Heritage Company site, Crewe - owned now by Locomotive Services Ltd. 03/20: to Ecclesbourne Valley Railway, as visitor at DMU Gala. 04/23: still at Ecclesbourne Valley Railway in operational condition. Moved to Cholsey & Wallingford June 2024. |
| External Structural Condition | Very Good |
| Internal Structural Condition | Derelict/Not Present |
| Underframe Condition | Very Good |
| External Finish | Not Applicable |
| Degree of External Originality | Much replaced/reproduced material |
| Degree of Internal Originality | Not Applicable |
| Degree of Underframe/Running Gear Originality | Some replaced/reproduced material |
| Degree of External Authenticity | Fair |
| Degree of Internal Authenticity | Not Applicable |
| Degree of Underframe Authenticity | Very Good |
| Rarity | Few |
| Historical Importance | no Immediate Importance/Not Applicable |
| Storage | Secure Open |
| Operating | Yes |
| Survey Date | 21/03/2000 |
| Surveyor | Gordon Maslin |
| Photo Date | 28/06/2015 |
| Photo by | Steve West |
| At Risk | No |
| Date Record Last Updated | 27/06/2024 |
