I've found this sound-library :
http://www.virtual-organs.nl/index.php? ... 58&lang=en
It's not free, and seems very interesting ...
the samples are tuned with a very scientific precision :
i think A= 440,0000 hz !!!
So there are some stranges sounds when you play several 8' stops together...
The result is very synthetic !!
I've detuned some stops +1.3 , some others -0.6 and so on with little random value.
And it sounds better like this.