This seems the weirdest organ tuning ever? Why does everything sound ... one whole tone up? If I had to guess it is probably a Werckmeister III or something too, but that really is insignificant with the 16% pitch (or speed?) increase
In baroque Germany there were 2 pitch tendencies. The chamber pitches were rather low (ca 392-420hz) and used for everything outside the church. Organs however were tuned in choir pitch, which started around 460 hz. In central Germany (Bach...) it was usually not very far from 464-465 but in Northern Germany it was sometimes higher than 490. The organ in Stade is usually slightly above 493 hz but it was summer and rather hot, so it was probably even some hz higher. The temperament was created for the restoration of that organ and is known as the Stade temperament. It's a kind of extended meantone with quarter comma fifths, but with more of them than in Werckmeister III, allowing some pure thirds to emerge.
