This may not be as thorough an answer as one might hope for, but I forwarded this question to Atlas Games, and got this reply from Cam Banks, the RPG Director there:
Good question! I believe the intent is that you treat the whole armor
suit as one item. You may get different answers based on whom you ask
over at the forums at www.atlas-games.com however.
So, I then asked the question on their official forums and got no consistent reply (yet, although more replies may come), and no specific books cited as sources. One answered with a question, another answered with "It depends on whatever your game master wants to do", and another said that there are too many books to tell definitively.
Still, I think that an email from the RPG Director of the company might count as a definitive source. Hopefully this helps.