Plan B put into operation this morning.
Decided to see if I could mount it on the mid mount grader. So a measure up and a bit of angle iron found.
BINGO! And no alterations to the grader.
I'll see if I can lay my hands on some plate at the farm. I'll maybe modify things and raise the disc up, to just below the grader blade. I'll see how it performs first. Used at an angle as shown, may push the sod outwards.