This piece is the little brother of the prelude n°10 in Em from the Well Tempered Clavier,
coming from the "KlavierBüchlein for W.F.Bach."
Here is my organ transcription (I've just add a rythmic pedal part.)
But the question was : what registration ?
I couldn't make up my mind, so here two versions : a soft and a loud one.
(and if you don't know the "Siloti" version, please, listen to this video :