GTA rear lights perspex covers

Does anyone know where I can source new or used clear set for 1989 GTA as mine are going dull. I saw someone had some organised a bunch to be made up up a few years ago from the following conversation thread
viewtopic.php?f=3&t=6592&start=30
Would really appreciate some help.
Rodney Apcar - Melbourne Australia

These was a small batch organised through FAR...one of the french forums, but I don't think there are any left and it was soft tooling so there was only going to be a limited run possible. The contact was Tim Paul. Chrome is your friend here if your french is as good as mine as it will dynamically translate the site.
Quality was OK rather than great, I think I was the only UK person to buy any and mine had to go back for retinting as they were originally clear, this was done with tinting spray.
If yours aren't cracked, I'd use one of the commercial headlight defogging systems (maybe start of with a fine grain abrasive a the GTA covers don't fade like headlights) and then retint them again afterwards from the inside if needed.
GTA rear lights are shared with Lotus Elan S2 and both car communities know they are like gold dust if not cracked (or generally to be honest).
Lee

Thank you Lee for the prompt reply. I tried cleaning with Vinegar and bicarb, toothpaste. helped a bit. Car polish. Even when to a place that stock a product NOVUS® Plastic Polish 2, they were kind eougfh to test on on the cover with no results. They told me perspex had discoloured, so I think any fine grit sanding will not help.

Use 1000 and 2000 sand paper and afterwords put a coat of paint laquer on them. They will look new