SOS ("Save Our Scotsman") appeal, seeking to raise a further £250,000 with the aim of completing the work by the end of the year. In May 2011, Flying Scotsman was unveiled on the museum's turntable, finished in wartime black LNER livery; after final tests, it was to be painted LNER apple green and have it running excursions by the summer. However, cracks were discovered in the horn blocks and further testing revealed more cracks throughout the frame assembly, leading to the replacement of the main stretcher bar, horn ties and middle cylinder motion bracket, all of which were deemed beyond repair. In 2012, with the project still unfinished, the museum published a report examining the reasons for the delay and additional cost. It found that the museum had greatly underestimated the work required due to the poor condition of the locomotive, much of which had been missed by a rushed inspection, which produced an overly optimistic assessment which was not based on engineering realities. It also found that once the project was underway, management lacked the experience, continuity or resources to undertake such a complex task, which was also hampered by illness and recruitment issues. Although the museum had a formal contract system to manage suppliers, managers failed to implement it properly. Problems were also caused by the conflicting objectives of producing a certified mainline locomotive while retaining as many original components and assemblies as possible, and between the need to overhaul the locomotive and use it as a marketing tool for the museum. The report recommended that the NRM consider the scope, size and responsibilities of their project management and engineering functions, and their contracting policy. Following the report, the NRM commissioned First Class Partnerships (FCP) to independently review the remaining work identified as necessary by the NRM, and make recommendations on how to proceed. In March 2013, the museum announced FCP had determined the locomotive would not return to the main line until 2015, and believed the outstanding work should be put out to external tender. Riley & Son was announced as the winning contractor, and on the same day the locomotive was moved to their workshop in order to return it to running condition no earlier than the summer of 2015. In April 2015, the boiler left the NRM to be reunited with the rest of the locomotive. Three months later, as restoration neared completion, it was