The plough is now in it's component parts. I did find that the adjusting screw and nut were not seized as I thought. It was the opposite end to the handle.
First I removed the disc. Now I'm not sure if this should go round. I would think so, but it seems to just revolve on a bolt.
Then off came the share.
That off, I removed the adjusting mechanism complete. I had to carefully prise open the brackets holding the nut. This was done with a little screw jack.
The next parts came apart with little difficulty.
Next came the difficult bits.
The block and pivot on the adjusting screw proved to be somewhat stubborn. The screw would just not turn in the pivot. Heat was applied to no avail, Eventually with brute force, but not ignorance I got them apart.
So the next job is to get things cleaned up and painted. That could be a bit off.