Organs don't work very well with Maize Sampler and even in Kontakt you need special scripts to make things like stops work correctly. None the less here are two instruments that give a nice pull out the stops and whale away sound!
VSCO2 Organ Win 64 Win 32 Mac VST Mac AU
Prudhoe Organ Win 64 Win 32 Mac VST Mac AU
VSCO 2: Creative Commons Zero 1.0 Universal : Versilian Studios / Sam Gossner
Prudhoe Organ: Creative Commons Attribution: Mark Beverley