They most likely are Lord and Lady and will have inherited the titles along with the manorial rights of the land on or around Oakwell. If you Google Manorial Rights it explains about how they were issued in the early 20th Century (100 years) as per the original statement. And Hardrof Limited was created to register these rights prior to 2013 to ensure they kept them.
Https://publications.parliament.uk/p...st/657/657.pdf
Bit of light reading for you there...