Thank you for your suggestions, I am hoping to commence the restoration as soon as I complete house alterations and we have to keep the ladies happy !!!.
I have had a bit of luck and acquired a original Parts book for the plough from a well known internet auction site for the bargain price of ?1.75, the parts book is for the "ENGLISH MODEL" of the Shearer Prince Plough although the printer for the book was in Adelaide Australia.
I probably think the variations would be in the plough mouldboards/shares to suit UK soil conditions as when I was in Australia I was told ploughing was shallow compared with the UK to maintain moisture levels in the soil.
The disc coulters seem identical to those on International ploughs, that two leg "wishbone" design rather than the more common single stem arrangement seen on other makers of the time. I wonder if International supplied them or Shearer copied them, must make a strong robust unit.