It’s always a difficult decision how to best secure the gluing edges of a front using either filler or wood, depending on how badly the gluing surface has been damaged.
In the past, half-edging used to be a common repair but is extremely intrusive and a huge amount of original wood is removed in the process.
In this case, I went along the gluing surface with a gauge and pressed a shaving into the area as it was too deep to just use filler.
Iris Carr Restorations 