Here is a game-ready Mailbox House, with stylized PBR textures included in the files. This has 535 polys (1035 tris) and 676 vertices.

Maps included in this asset are the Base Color, Normals (OpenGL and DirectX), Metallic, Roughness and Ambient Occlusion.

As an added bonus, the World Space Normals, Curvature, Basic Normals, Position, Thickness Maps and the Color ID have been added for any re-texturing, along with a UnityPackage file.

This asset was rendered in Marmoset Toolbag 3.