ok - I'll update this as I go because I'll forget.
I used this product.
https://www.whitworths.com.au/starbrite ... ep-1-237mlWith some solid arm work, it pulled a heap of micro scratches out of my two good ones and somehow got all the red mud out of all the sandblasting on the rear. The rear is still super hazy from the sandblasting... I'll have to get my hands on a buffer, microfiber and arms aren't harsh enough to bring it down.
I already have this product floating around for detailing purposes. It polished up the two 'not bad' windows amazingly, and made the sandblasted rear shiny. Also meant I can now feel all the pitting in it.
https://www.bunnings.com.au/vuplex-375g ... r_p1284749I got a quote of $350 to replace the rear, while it's expensive. If i cant polish it out, then I've gotta pay for it anyway so the stakes aren't as high now.