The geometry was created in Blender-3D. And made available as obj-files. The images-textures created in Blender-3D and GIMP And made available as jpg-files. The above pictures were rendered in Blender-3D. No post-work other than resizing.
The readme.txt file lists suggested surface sub-division levels for each object.
Picture No.3, above, shows the shotgun handgrip folded up over its trigger guard. Picture No.6 shows model without texture files and without any surface sub-division.