This stucco chimney would need some work on the stucco itself repairing holes and worn portions of stucco. This would require scaffolding and very hyper curious work by stucco and painting crews. 

This chimney cap is rusted and 30 years old plus. It is going to need to be replaced as the chimney is being repaired. Our recommendation is to remove this Chimney when we are reroofing so that there’s no need to restock oh repaint and add a new chimney cap on.

Because this is a gas chimney It would be easy to bring a double wall pipe through the roof and flash to this. That would look something like the pipe shown here. No maintenance required easy assembly.