I'm obviously specifically interested in the Gallery where the H4 is displayed. What does the gallery look like? What does the display look like? But also if there are any convenient corridors nearby where someone might conceal themselves in a broom closet or similar until museum closing time (they have magic SF tech for the actual theft though any details of security would also be useful - I'm assuming the H4 is in a glass display case, for instance).
I've checked out the museum web page (here) and tried Googling "National Maritime Museum Greenwich", "National Maritime Museum Greenwich interior" and "National Maritime Museum Greenwich layout" both in google and in google images. I've found some architects drawings (Rich Mather's Web Page) but these are difficult to interpret without, in particular, knowing the location of the H4 within the museum. I was hoping that the museum would have its visitor map/pamphlet online but have been unable to find it. If it is online and someone has a link that would be great!