After simmering the cones for about an hour, I left them to soak overnight, then strained off the liquid which was a deep brown. I then covered the cones with fresh water and simmered again. This liquid was a little lighter brown in color, and I added it to the first liquid. A 2 oz. skein of wetted wool yarn went into the dyebath and was left to simmer for an hour before turning off the heat and letting it cool in the bath. The color was a very regal gold.
There still being quite a bit of color left in the dyebath, I added 1 tsp. of copper mineral salts along with a new 2 oz. skein of wetted wool yarn and allowed it to simmer for about 20 minutes. I was hoping for an olive green shade, but the color was still just golden. A second tsp. of copper and one of iron added to the dyebath and simmering the yarn for another 10 minutes resulted in this lovely green:
note: Remove the yarn before adding mordants (which have been dissolved in warm water) to the dyepot. While I am happy with the color, and the yarn still feels nice and soft, I think that next time I would begin with only 1/4 tsp. of iron and add more if needed.