Your local RV shop sells the current replacement burner for Bowen/Atwood water heaters. More than likely, it will not fit your water heater without modification. By "sensor line", I assume you mean the thermocouple. They sell that too.
Proceed carefully at this point if you plan to repair this unit. Will the tank hold water at pressure? It may be rusted out. The burner & thermocouple will set you back at least $50. Plus time to modify it if it can be modded. You won't know if the Control valve/thermostat works until you try to use it. $100 would fix that problem, but I would highly recommend replacing the water heater if that part is bad.
The perfect solution would be to find an old water heater for parts - Check with your local RV place.