Beautiful map! I'm late to the thread, and being a lazy bastard, haven't read everything, so if you've already addressed this, just tell me to shut up.
I'm not in love with the periods after the numbers on the map itself. Perhaps those would better fit in the key alone, not in the map rooms.
I'm also a tad confused by the capitalization in the key. It's probably just me, but I'm not sure I understand why some words are capitalized while others are not. Are they proper names? If so, why are some descriptions proper names while others are not? Because other viewers may be as obtuse as me, I'd be inclined to fall back on the usual title capitalization rules throughout your key (capitalizing all first words, nouns, verbs, adjectives, adverbs, relative pronouns over four letters in length, and all other pronouns, but not conjunctions, prepositions, articles and the like).