I spent simply ages working out the pattern repeats for this border. I had to fit in 11 X 6" down each side and then start the corner treatment 3/4" away from the corner. After much playing with compasses I go it right. I cut the cardboard edge stencil so I could mark the placements. Did it fit when I got to the next corner? No. Much blue air round Toad Hall today. Never mind 'I have a plan' which I shall reveal if it works. If it doesn't, just look skyward towards Toad Hall and see the blue cloud.
I traced the shape six times onto freezer paper, layered it 6 sheets deep then freemotioned without thread along the lines. I have done this before but this time, I put my foot to the floor and moved the paper slowly. This was brilliant, it 'cut' the shapes for me.
Then using a glue stick, I glued each side of each shape, clipping into the concave curves. I didn't fold the ends over as they shall be covered by the next piece.
Just laying these few out on the table, I'm pleased to see they look as good as I expected.