A 1930s steam engine which was bought for £50 in 1950, has been sold at auction for £911,000.
The Lion was one of four showman's road locomotives built by agricultural engineers Fowler for the West Country travelling fair Anderton and Rowland.
Built in the final days of steam, it powered fast and popular fairground rides until it was retired in 1946.
With a price guide "either side of £1m", auction house Bonhams said it was sold to Saunders Steam Collection.
Steam enthusiast Mr Saunders said it was a "late birthday present" to himself.
Tim Schofield, from Bonhams, said the ornately painted locomotive had "put on quite a show" when it steamed in to New Bond Street earlier in the week.
"It was delivered at 4 o'clock in the morning and two engineers lit the boiler and after two hours it had got to operating temperature," he said.
"At 7am it drove the correct way down New Bond Street, down into Brook Street and did a two-point turn to reverse into the saleroom's yard."
He said the Lion had only had "three owners from new" and had spent the last 70 years in Salisbury in Wiltshire.
"It worked with Anderton and Rowland up until the Second World War and in 1950 it was acquired by its second owner Ernie Lucas of Salisbury for £50," he said.
In the 1990s it passed to its third owner - Arthur Thomson of Salisbury - who spent two-and-a half-years restoring it.
The auctioneers said following a "lively bidding battle between bidders from the UK and the USA" the 1932 10hp B6 Showman's Road Locomotive had been sold to the Bedfordshire-based Saunders Steam Collection.
"It's one of the largest steam collections in the UK," a Bonhams spokeswoman said.
"The new owners are looking forward to showing the Lion at steam fairs and shows next year."