This is Zvezda's 1/35 BM-13 Katyusha kit, based on the Zis-151 truck. The vehicle was destroyed in a training exercise of some sort, possibly a target practice drill, and has been exposed to the elements for some time.
A dog-related accident coupled with a mishap with glues and paints ruined the model's original paintwork and broke several key components, so I thought I'd try something different and model a heavily-rusted vehicle. I damaged my model further with fire and a good pair of pliers, then used Vallejo acrylics and pigments for the rust, followed by washes, drybrushing, and dust. The groundwork and rocks are grout, while the plants are made out of old paintbrush bristles. The pieces of wood that the real suspension is propped up on are matchsticks, stained with artist's oils and pigments.