Specsavers are doing free eye tests Al
If you look at the shiny 1 you'll see the top bits of the wings slope thicker

the thickest part is the same so i think it is just the wings that are reinforced, probably to stop flex and letting the bolt undo, stupid thing is that when you tighten them up they have nothing to stop against so you can just keep tightening them til they snap or push down the cover, stupid idea completely
I'd have had a threaded shaft that screws into the cradle which has a thicker shaft and a nut on top to push the clamp onto til it stops and can be tightened up.
I can still tighten up the bolts relatively easy despite doing the torque and 180 degrees

56 350 2.2 130ps mk7 with 2 side doors
65 290 2.2 125ps custom with 2 side doors
07 350 170ps
Ids v86 licence + v86.04 update + xprog
hereIds map
here