Thanks everyone. I’ve taken some photos & found the user manual. Unfortunately, there’s no diagram or illustration that shows how to replace the corks.
I’ve noticed that there is also play in the arm (black piece of steel in the photo) when it moves left-to-right when selecting forward and reverse.
On a side note - I know the farmer that sold me the machine. His property is dead flat. He had a puncture and just replaced the tire with whatever he had sitting around.
Thanks everyone for your replies so far!
