Matt,
It looks too thickly cased to me, but, in the link you give it, it also says "K, R" under the image. Translated that means 'Kingfisher' and 'Ruby'. No mention of Aubergine - or perhaps amethyst.
I haven't checked any other references, so if you find an "A" under another illustration of this shape number in the catalogues that would help support your case.
Cheers, Nigel