If you listen to a band like Renaisance, or any prog/folk band you can hear how they have a lot of different instrumental colours that can provide a nice contrast when giving the voice a rest. Some tastefull 'chamber' embelishments would really lift this track, or even a little bit of keyboard / synth. I think the backing vocals over stay thier welcome occasionally, one of the tracks has a lot of vibrato that grates after a while.
Anyhow this is all about making the track more compact and captivating. This would be icing on an already fantastic cake.
Thanks for sharing this.