In July 2016, 7027 was purchased from the Waterman Trust for an undisclosed sum by Jon Jones-Pratt, owner of 4936 Kinlet Hall and the revived Crosville Motor Services, who planned to restore the engine to full mainline standards.

In February 2018, agreement was reached between the West Somerset Railway and Jones-Pratt for Thornbury Castle to be moved to Williton, to be restored there over a six-year period.

[3] An April 2020 report stated that restoration had started; the project was headed up by the chief mechanical engineer of Great Central Railway, Craig Stinchcombe.

[5] In August 2022, the future restoration of Thornbury Castle was called into question when the Great Western Society's 4709 Group bought the locomotive with the intention of donating the boiler to its project to re-create a GWR 4700 Class.

[14] In May 2023 The Railway Magazine reported that the use of the Castle's boiler for the Night Owl project had been confirmed in an announcement on 24 April by Richard Croucher of the 4709 Group.