Sorry Trustmeimamechanic but to some extent I disagree. A vehicle-be it an aircraft,tank,truck or ship is an object just like any other and while maintaining it in running order might be better mechanically it often does not help to preserve the rest of the object. Take the LRDG Chevrolet at IWM Lambeth or Corsair KD431 at the Fleet Air Arm Museum as examples of a truck and aircraft which if restored to working order would loose much of their originality and history in the process.
I do agree that having a vehicle in running order is often very evocative,but it is not the be all and end all of preserving a vehicle,a non-running truck or aircraft in original condition,perhaps still bearing the scars of war,can be just as evocative-if not more so.
To answer GWT's original question,Yes I would consider selling(or maybe donating)a vehicle to a museum but it would depend on the museum in question as some(in the case of aircraft museums)tend to see vehicles as "dressing" for their larger exhibits and not necessarily worthy of proper care and preservation.