Right then, I removed the plastic surround, just so I could see what to play with, and found this:



I assumed the two star-nut things (I din't know their real name) were the adjusters, and I adjusted away. All good, until the nearside rounded off, and it doesn't have a shape enabling the use of another tool. So it's kinda stuck where it is. It's not level with the far-side (as far as I can tell in the daytime), so will go out for another play at night to see what it's like.
Trouble is it needed to be changed for MOT, so hopefully it will pass.
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