Thanks for your comments! I was worried that the transition back to D major in b. 44-46 was inelegant, reinterpreting the A sharp as a B flat, but I hope it lends a nice little harmonic surprise.
I'm probably betraying my background as a wind player in preferring to keep the strings as accompaniment. I agree the melody would sound well in the violins, but I guess personally I prefer the way it sounds on horn and oboe.
I may revise this a little, though, as I finish up the piece. I'll post the whole suite when it's finished.