Just my 2 cents after studying this thing for a while... The ideas I have below are what I have been basing my back pack assembly on. Can't post a picture, so bare with me if you can
I think that the front/back is all one peice with a metal brace of some sort built in underneath. The entire back-pack assembly can be removed - possibly in 2 parts; the cage and tanks.
When you look at the bottom part of the back armour, there appears to be a hinge (but it's not a hinge, it's a bar - there are a couple excellent pictures of this) which is attached to the armour itself, and is not part of the tank/cage assembly, but the hooks on the tanks/cage assembly are hung over it.
I think there may be a slide connector on the back of the armour (similar to how the new E11's are attached to the regular troopers). Attach the back pack by aligning the "pin" or "pins" into the slots on the back of the armour, then as it slides down, align it so the cage-hooks snag the bar, which is part of the back armour assembly. (Maybe that curly wire we see in the pictures on his upper left side is the cage release pull).
With a 2-part assembly, the cage can be mounted to the back, and then the tanks can be added when needed.
Rob
