Partial success.

This is a vent out of Daisy, the pivot holes for the link that joins the vanes had broken, and the wire I've melted into place and formed a new link with is my attempt at a repair.
It does work but the problem is the post at the lower left here, it's misshapen and binds slightly at this fully closed position resulting in a bent link wire if it's opened by pushing a finger in the spot cast on it, but that isn't a real problem here as we always have vents open and even if shut it's easy enough to push the other vane to open them.
This is the second vent on Daisy to break so a definite design weakness methinks. To be fair to Proton though there's bugger all else I can moan about.