I used tiny spots of glue to secure individual threads onto a tape, so they could not slide out if the edge of the cloak was trodden on.

I had already sewn the tape in place before turning up the hem - it is a common trick on curved hems to use a bias tape and make a fairly narrow single layer hem with the raw edge covered by a tape.

If I could have got an iron on tape that would curve I would have used that, but as with a lot of things in garment reconstruction you take what is available and work with it.

The iron on interfacing is a life saver as it stabilises cut edges, reduces holes and then withstands washing.

Once in place you can sew through it to restore the seam, even if you are right on the edge of the remaining cloth, because the threads are held so they can't start to slide through the stitches.