2000 Chevrolet Silverado 2500 Mechanic / Service Truck

2000 Chevrolet 2500 Silverado truck with 6.9 Liter Gas engine with automatic transmission. Has had recent tune up, oil change and new battery. Truck starts right up and runs fairly rough until warmed up. Runs smooth after warm up. The service light flashes on and off until warmed up. Has Stahl service bed with ladder rack on top. Rust on both sides of outside of bed. interior of bed is good and has 2" reese hitch receptacle installed. A few minor dents and scratches. the interior is ok. driver side door lock button is missing and driver side arm rest is torn and taped. heat and A/c works, radio turns on but has no sound. truck is ready to work.