Sir William McAlpine died on Sunday at the age of 82.
Sir William, a former director of his family's construction company, purchased the famous steam locomotive, built in Doncaster in 1923, from America in 1973.
It had been due to spend the rest of its days in a museum but Sir William brought it back to England and pressed it back into service for day trips before selling it in the Nineties.
A keen rail enthusiast, he built a full-sized railway at his estate near Henley including the original station from Somersham in Cambridgeshire, which was closed during the Sixties.
Born in London in 1936 at the family-owned Dorchester Hotel, his great-grandfather was Sir Robert McAlpine, the first of the McAlpine baronets and the founder of the construction company.
Built for the London and North Eastern Railway at Doncaster to a design by Sir Nigel Gresley, it became the first steam locomotive to be officially authenticated at reaching 100 miles per hour on 30 November 1934 and then setting a record for the longest non-stop run by a steam locomotive when it ran 422 miles on 8 August 1989 while in Australia.
After a ten year overhaul by current owners the National Railway Museum in York, the loco re-entered service in 2016.