The prototype has Afterlife/Frozen Empire - style strain reliefs on some of the replica pneumatic hoses… While I imagine this wouldn’t be a dealbreaker, it’s not accurate to how they looked in 1984.
The red label on the Gear Box should be located more centrally, rather than veering to the left-hand-side of that part of the Pack.
The lower section of the grey elbow on the HGA looks far too short.
The mounting screws should be Cap-Head-style with washers underneath. Silver button-head-style screws were a detail first found in the 1989 Proton Packs.