Is it a British Mild or more of a brown?
For a mild, I would sub in some Maris Otter (7-8 lbs), 2 ozs. of Special B, 3 ounces of flaked barley, 1.15 lbs of Crystal 40, bump the chocolate to 5 ozs., and drop the Crystal 20 to 2 ozs.
That changes your recipe drastically, I know, but I just made a mild that was my favorite yet with that recipe (but I had no honey malt in it). The foregoing will get your SRM right, just not sure the flavor profile with the honey malt, but I bet it will be superb.