THE restoration of Flying Scotsman should finally be completed by the end of the year - too late to get it back on the tracks in the summer, as had been hoped.

The National Railway Museum's project to save the iconic steam loco, which began in January 2006 and was originally scheduled to last up to two years and cost about £750,000, has been beset by technical difficulties.

The museum said last January it hoped Scotsman would finally be fit to operate by this summer but a spokeswoman said it emerged later last year that it was necessary to manufacture new sections of the loco's frames, and this additional work meant completion by summer was now 'highly unlikely'.

She also revealed that once the return to mainline operation was complete, a commercial partnership agreement had been reached under which a Bury firm, Riley & Son (E) Ltd, would manage the operation of the locomotive for two years.

"This will include a programme of ongoing maintenance and helping to resolve any issues that may arise."

Scotsman will be painted in BR ‘Brunswick Green’ livery and carry the number 60103, she said, and the total cost of the project so far was in the region of £3.8 million.

She said it had been decided to manufacture new sections of the frames when a trial fitting of cylinders showed how badly out of alignment and elongated the mounting holes were.

"Although some remedial work in this area was expected, the amount of welding that would have been required could have led to potential deformation of the frame plates."

She said the new frame plates were manufactured at Arthur Stephenson’s Engineers Ltd in Greater Manchester and welded to the original frame of the 1920s locomotive at Ian Riley & Son (E) Ltd's workshop in Bury.

Further works in Bury included trialling and the final fit of components and reconstruction including the attachment of a new front buffer beam plate, and full ‘running-in’ testing.

Museum director Paul Kirkman said: “We are still progressing towards completing the restoration this year and we are planning a whole season of events and activities from February 2016 celebrating this star locomotive in our collection.”