The Cronus B Deck Armory is unlabeled on the map. One can find it by matching the symbol located in the scenario description.
It is located on the left hand side under Vestibule 1. There are 3 little armory rooms with 2 doors each.
Please add an armory label. Possibly right under 'Vestibule 1.' Players seeing 'Armory' on the map will surely make a beeline for it imagining a ton of gear.
Page 123 for Cronus map.
Page 128 for B Deck Armory details.