Well, Mirage have received the parts I sent back for them to examine, and have confirmed they don't fit
So I'm not going mad!!
I've asked if this is a general problem or on a specific run or something. We'll see what they say. At any rate, they have none in stock (strangely - they said they'd fitted a pair to a car not a couple of days ago....
)
I suspect that this particular Edit part is just plain the wrong shape. Not a very good show when you realise this one doesn't fit and the front alloy brace doesn't fit without adding 0.5mm shims all over the place...
I've asked when they expect stock, and we'll see if I wait it out or not.