Hello Mike,
The Great Eastern was indeed laid down as the Leviathan. The cost of her launch exhausted the owner's funds and she lay unfinished for a year. She was sold to new owners called the Great Eastern Ship Company who dealt mainly in the Far Eastern trade (hence the change of name). She was built by Messrs Scott, Russell & Co of Millwall, London, with a tonnage of 18,915, comination paddle wheels and single screw with a maximum speed of 13 knots. She had six masts and an incredible five funnels. Her keel was laid on 1st May 1854 and she was launched on 31st January 1858. It was decided that she would be more profitable on the New York run - she had cost $5,000,000 after all! Her maiden voyage was 17th June 1860 but she proved unpopular and became a cable layer four years later. She was scrapped in 1891.
Regards
Geoff