Though painted and presented as a Late War Hetzer at the Imperial War Museum in Duxford, this in fact is a Swiss manufactured copy of the German WW2 self-propelled gun/tank destroyer. It had a crew of 4 and was armed with a 75mm gun and one machine gun.
The vehicle is a post war production model made by Skoda for the Swiss Army in 1947 (which designated it G-13). Vehicles were manufactured on the wartime production line and in many cases left over wartime spares were used (so Swiss G-13 vehicle parts sometimes carry Third Reich parts stampings). Indeed anecdotal evidence suggests some hulls were recovered from the battlefield, remanufactured and sold on to the Swiss (who used them until 1970). The main difference between the 38(t) and the G-13 was the use of a Saurer diesel engine, instead of a Tatra petrol engine in the majority of Swiss vehicles. The IWM example has a diesel engine.