Just a quick update today, what with being at work until 17.30 and the torrential rain most of the day I didn't have a lot of time to work on her today.
I removed the tape and the repair to the inside edge appears to be solid.

I also gave the back a quick sand to remove the worse of the gaffa tape residue

I then filled the minor cracks with some super glue

And gave it a sand while the glue was still wet to seal them nicely

And lastly I have packed the small crack in the face with glue and will leave this to set over night.

That's all the repair work now done. Once the glue on the face has set I will need to fine sand the bat all over, apply a scuff sheet and put some bat wax on the exposed willow.
I'm fairly pleased with the way this has come out so far, especially considering the state ti came to me in. Once I've finished the bat up I'll post some final pictures of how it looks when I return it to the owner.