organ recital in unequal temp

http://www.bbc.co.uk/programmes/b00nydtp

Unfortunately the presenter, while smirking and chuckling over how wonderful the player is, doesn't give any credit to the organbuilder who is actually responsible for the sounds coming out of the instrument, Aubertin!

With some diligence you will find which temperament was chosen but it is more fun to guess.
Best, ~~~T~~~