The 76-year-old express will make its first run after restoration from its former King's Cross home to York on 4 July. Tickets will cost enthusiasts £350 each.

Dr Tony Marchington: "If I had not done it she would not have been restored"

Built in 1923, the Scotsman ran on the London and North Eastern Railway for 40 years, completing some two million miles of service between London, Newcastle and Scotland before being withdrawn in 1963.

It was the first locomotive to achieve an authenticated 100mph speed in 1934 - some claim the City of Truro beat the Scotsman to it, but that run was never proved.

After 1963 it had a succession of private owners, including pop impresario Pete Waterman, but was finally left to decay in a shed.

Dr Tony Marchington, 43, of Oxfordshire, bought it for restoration in 1996 at a cost of £1.5m.

Tony Marchington: "Wherever I go people have heard of her"

"At the time there were many sceptics who doubted my determination and financial ability to complete the task," said Dr Marchington.

"I must admit it was a daunting prospect, but there was no way I was prepared to let this magnificent example of Britain's railway heritage fade away."

Flying Scotsman began taking shape again at the former Great Western Railway shed in west London.

Experts enlisted to work on the project included the locomotive's chief engineer from the 1980s, Roland Kennington and ex-British Railways man David Ward.

This was the most extensive and expensive steam locomotive restoration ever undertaken, said Mr Ward.

"We set out to reach Rolls-Royce standards and I am confident we have achieved it," he said.

Brief history

• Flying Scotsman was built at Doncaster in 1923 to the design of rail mechanical engineer Sir Nigel Gresley.
  
• It was chosen to represent the latest in steam locomotive design at the British Empire Exhibitions in 1924 and 1925.
  
• When Flying Scotsman was withdrawn from BR service in 1963, Nottinghamshire businessman Alan Pegler bought it for £3,000.
  
• In 1968 an LP called Flying Scotsman included the sounds of the loco steaming its way along the tracks.
  
• Builder Sir William McAlpine bought Flying Scotsman in 1973.
  
• Dr Marchington bought Flying Scotsman after the restoration plans of Sir William and pop impresario Pete Waterman ran into financial difficulties.