I started doing the Discovery 3 wheel arch conversion a few years ago, but due to moving house in 2020, I gave up on it. Partly because I only had one side . But I bought a brand new set of Disco 4 arches, cut them around to fit, but they're made of a more brittle plastic that has no give, so they're too stiff to conform to the Freelander arches.
I think I'll have another go again in the summer !