British Spanners were always larger and clunkier than their US counterparts, this is a 1" x 7/8 Whitworth.
You will be purchasing a scale model of a real item. The model may require removing of supports and some sanding and filling. We would recommend washing in some warm soapy water or Isopropyl Alcohol before painting to remove any remaining residues. Hanging Straps are indicative of how the packs were hung but the straps may not be suitable for your requirements and are fragile so would be best replaced with tape straps.
