VWHeritage used have these, though I believe they were made by SSP back then, but were showing out of stock for quite a while.
I rang them a few weeks ago to see when they'd be back in to be told they were no longer available and it'd be unlikely they would be getting more.
The only other source I could find at the time was an eBay seller who was asking more for them, plus the now obligatory additional postage to N. Ireland,
Looks like things have moved on since and these genuine ones have just appeared - not sure if they're back for good, but if not now you know just in case you're in the market for them and don't want to pay over the odds.
VWHertiage (https://www.heritagepartscentre.com/uk/1h0501639-rear-axle-cover.html)
(https://www.heritagepartscentre.com/media/catalog/product/1/h/1h0501639_1_1.jpg?optimize=medium&fit=bounds&height=700&width=700&canvas=700:700)