In fact they have something a little bit "agressive" in the trebles (metallic).
In the same time, I'm not a specialist in this area (i never mixed folk guitares, only electric or nylon)....
Yes, metallic is the right word, the guitar sounds a bit ,let me say thin.
I would boost the low frequences a bit more and take something away around 8-16kHz also I would try a reverb on the guitar to make it a bit more warm.
By the way, this is a nice song.
Thanx for your honest answers. I think I might try to re-record completely, may be with a spanish guitar instead. Try to give it a softer, warmer flavour. And something better in the bridges perhaps...