✅ Running number D5531. ✅ Airfix 54101-9. TheAirfix 54101-9 BR Class 31 Diesel Locomotive, numberedD5531, is a classic OO gauge model finished inBritish Rail green livery. A versatile Type 2 diesel, the Class 31 worked passenger and freight services across Britain and remains one of the most recognisable BR diesel classes.
