If there are no chips in the rails it's a great piece and much sought after. No need to change it at all. The D is a good middle of the road tip opening ( 76) that I would use myself. C is a little close and F on the open side. C*, D and E are the most popular.
The D could be a little open for an 11 year but I wouldn't lose it. Best to get the horn in good playing condition.
The D could be a little open for an 11 year but I wouldn't lose it. Best to get the horn in good playing condition.