Red Combine Harvester 3 (Polygon mesh 3D model) is available on CGTrader for $139. Original author: 3D-Horse. Specs: 1029833 polys, 1065022 verts.
OBJ (OBJ, filesize: 54.9 MB), HRC (Autodesk Softimage, filesize: 41.8 MB), MAX (Autodesk 3ds Max, filesize: 65.7 MB), 3DS (3D Studio, filesize: 10.2 MB), LWO (Lightwave, filesize: 12.6 MB)