Pretty amazing how much "work" steam can do before it "dies". That really only qualifies as double expansion however, as the D10's cylinders are being fed simultaneously, not consecutively, or rather simple not compound.
As to your packing glands, perhaps try loosening them slightly and adding just a bit of steam oil, then tighten them back again just a bit more than they were before. If the gland nut hasn't been "bottomed" yet, then there is still "packing" available, but some fresh lubrication there may be of help.