Might be coming time to retire the coronet...

Only you can decide what will work best for you, but I'd try to hang onto it as a daily driver. You've rebuilt the engine so you know that's dependable. The time will probably come when you won't want to drive your Duster all of the time for fear of it being damaged. I can speak from experience that motorcycles are fun, & I've ridden in weather which kept most people in their houses, but they still make lousy daily drivers in most areas.