[Horrgakx]

Thanks for taking the time to do that and post photos!

I have managed to pull the knob outwards, twist it, and it locks in place ready to be inserted.
However, when I shove it up the hole until it stops but it only grabs partially and the knob doesn't spring back and lock it into position. I even tried a rubber mallet to give it some persuasion but it won't lock. I can wiggle the bar downwards and out.