trailer footstep 3D model is available on CGTrader for $2. Original author: SuryaAlexander. Specs: 1500000 polys, 1500000 verts.
STL (Stereolithography, filesize: 30.3 MB), OBJ (OBJ, filesize: 168 MB), FBX (Autodesk FBX, filesize: 31.1 MB), OTHER (Other, filesize: 39.7 MB), BLEND (Blender, filesize: 39.7 MB)