Hereford 46 stop version
"Serenata", is from the St. Cecilia Series of organ compositions, recently back in print. You can order (and see) the music here:
The Solo: Harmonic Flute 8'(right hand accompaniment at beginning ) and the Viola da Gamba and Celeste 8' (B section) on the Hereford Willis sound luscious on this piece....... at least I think so!
Not difficult to learn, although there are a few tricky spots with some "strange" jumps in the right hand, and a few pesky accidentals that crop up. The piece doesn't come to life until you add the phrasing, expression and choose a balanced registration that brings out the left hand melody, but doesn't cover up the colorful right hand accompaniment.