Hi Gm nut, I posted a pic like this somewhere else on the forum but can't remember where now. The Rare Spares / Kingswood Country spoiler is way off. For comparison I took my old fibreglass reproduction one and placed it on the same angles. I ended up getting a new fibreglass one from a place near Sydney. Not really a help for you, but I was very happy with their quality and fit. I can let you know the detail if you are interested.

SpoilerComparison.jpg