I'm not sure this is the right thread, but I asked David Berry who worked on the production of A New Hope at ILM for any information regarding the spacetrooper backpack. I got this answer Sorry, I am afraid that I do not have any information on this. ILM did not manufacture any of the costumes for the first Star Wars film. If I were to guess, it would've been the English crew working from concepts based on Ralph McQuarrie's designs (or maybe Joe Johnston), but putting their own spin on the final design. But again, that is a guess, what do I know, that was a long, long time ago...Cheers, DaveB
It is not any news per se but I'll keep on digging!