I've finished the plying and washed the yarn! I ended up with 375 yards of heavy fingering weight, 3 ply yarn. It's a very dense yarn because of the way I spun it (worsted) and because Border Leicester is not a particularly crimpy wool (kid mohair doesn't have much crimp either). I love the way it came out and I think it will be perfect for socks, which was my original plan. It should wear really well.