Thats a generic Airbrush with LOW and HI-Res Models to Render with all the maps needed and a 3D print version,since it could explode even printed in Nylon or PTEG the model is NOT hollow to avoid temptation of use their body to replicate a real one..it´s only intended to decorative or comercial expose pourposes.I suggest using the decimated model for the render but you have four models from 90,000 polys to 6 million polys as 4 separate Zbrush subdivisions of the same Quad model to avoid needing even to install ZBrush. Being a completely chrome object it does not need a complete format PBR to save two maps, unless you want to make them yourself, the base color map and the metallicity map, in Arnold Render the base color used in the renders you see is a medium gray (HSV 0.000,0.000,0.503 -RGB (from 0 <255) -128,128,128) and a metallicity of 0.992 ... and that's it, the remaining maps are in 4K and are the same for all the models,recomended not use the displacement map in the decimated model ( don´t need it) neither the hi res quad models cause distort the mesh too much...and if you need a clean model without scratches only need to change the Roughness map for the appropriate in the same folder...