Doesnt the shaft need to go through a bearing before you fix the key?Some awesome suggestions guys cheers. So I have been out there, there has been progress and I have been videoing!
No more than a few minutes of useable stuff but I'll edit it tonight and get it up asap.
I am particularly liking the "weld in the key" suggestion. when you see the sheer amount of damage on this shaft, that's probably where this is heading.