Part of a renowned steam engine has been lost during its road journey to Norfolk – prompting an impassioned plea for help from the restoration team.

The King Edward II is one of the last three surviving locomotives of its class, which will start its six-week guest appearance on the Mid Norfolk Railway on Saturday following a �750,000 rebuild.

But during last night's journey by low-loader from Didcot, in Oxfordshire, to Dereham Station, the polished brass safety valve bonnet, which usually sits proudly atop the restored engine, went missing.

The part is about two feet tall, with painted blue side-pieces.

It is believed the transported loco may have hit a low-hanging tree in the Swaffham area, and the part could be laying by the roadside on the A1065 between the A11 and Swaffham, or the A47 between Swaffham and Dereham.

George Saville, part of the restoration team, said the part would be relatively worthless as scrap – but priceless to the volunteers who worked on the 22-year project.

'We just hope it doesn't find its way to a scrap dealer,' he said. 'It is very thin metal, so its scrap value is minimal, but it is priceless to us. To make it again would take a very long time.

'It was an original, and they spent hundreds of volunteer man-hours on it. If anybody can get it back to us we will look after them and make sure they get a ride on the train.'

Anyone who thinks they have found the safety valve bonnet should contact George Saville on 07974 907788.

For a full report on the King Edward II's arrival at Dereham, see tomorrow's EDP.