Looks like Recaro is releasing the same seat that goes into a defender here in the US for off road vehicles in 2020.
https://www.recaro-automotive.com/us/dynamic/recaro-cross-sportster-orv
A little searching and i found this ...
adapter Brackets
https://www.lucari-solutions.co.uk/...one-seat-fits-land-rover-defender-90-110.html
and these to remove the seatbase.
http://www.recaro-seats.co.uk/land-rover-defender-adapters.php
https://www.recaro-automotive.com/us/dynamic/recaro-cross-sportster-orv
A little searching and i found this ...
adapter Brackets
https://www.lucari-solutions.co.uk/...one-seat-fits-land-rover-defender-90-110.html
and these to remove the seatbase.
http://www.recaro-seats.co.uk/land-rover-defender-adapters.php