Armory items cannot be put manually on display. Use the Display Prep Station in the Curator's Office or put them in the 'Armory Storage' cabinet at the stairs to the armory's lower level for them to display.
SSE: This item shares its display space with the similar items Dawnguard Black Armor and Dawnguard Medium Blue Armor. However, all three have separate entries in the MCM, so they will all count for the museum's total display count.
Classic: Only one of the three items can be displayed at a time.
