I think you're off to a great start here Mardon ...
:cheers
Don't be shy, give up your suggestions (if any) on how to further improve upon this most impressive piece if needed. This is an integral part of the suit that most people are too intimidated to approach (myself included). It's also a piece the Fett community has been in desperate need of .. combining accuracy with durability and ease of assembly. With all of our suggestions as a unit, we can all help this project along .. for the good of the many (I know, that sounded like Star Trek, so shoot me 
)
I'll be the first to step up to the plate here, with a couple if suggestions .. one artisan to another, and reserve my place in line for one of these when completed.
In final production, it might be best for weight concerns as well as durability .. to cast the rocket assembly in fiberglass. If it's hollow, it's lightweight, but stronger than a solid resin piece that can simply break in two if dropped or hit on a doorway.
The only other thing that sticks out to me, is that the main tank may be too large in diameter. But it could be distortion in tthe perspective of the pics.
With this pack cast in fiberglass, there is a possibility that it could be one of the most durable packs, as well as one of the lightest packs .. as light as a styrene pack in fact .. 
