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14 January 2015 Last updated at 18:28 GMT
The carriage has spent four months at Locomotion, the National Railway Museum in Shildon.
It took the World War Two prime minister's coffin from London to Oxfordshire in 1965.
The restoration cost about Â£30,000.
Look North's Ian Reeve reports.
A railway carriage that carried Sir Winston Churchill's coffin to his final resting place has been restored in County Durham.