All furniture will eventually deteriorate completely. Most antiques have experienced some sort of breakage or will in the future. I have 2 principles that guide me in attending to repairs.
Maintain the integrity of the object.
Respect the historical and physical distinction of the piece.
The application of these principles involves preserving as much of the original components and character of the piece as possible. Simply put; do as little as possible while stabilizing the piece from further deterioration.
Repairs should be reversible. Some day they will deteriorate also.
Missing veneer should be replaced with little surrounding
material being removed.
The original type of glue should be used.
Any wood replacement should be done with the same period species.
All treatment should be documented.
Preserving the value and appearance of you cherished piece is my objective.