Spiral winder display caseback for vintage omega

Sorry if this has already been discussed before, but my searches only found people discussing the spiral winder caseback for the modern speedy.

I was wondering if anyone has had experience with his caseback for 60's seamasters and constellations.

I have been considering one, but been unable to work out if it would fit a c line constellation case.

Alternatively if anyone is aware of any other display backs that might fit I would love to hear about them.