[elgyqc]

Originally Posted by Homeoboxter

... Your bores seem damaged because of the pistons seized in the bores due to the lack of lubrication...

The pistons did not seize... they all slid out normally when I separated the cases

Originally Posted by Homeoboxter

What do your pistons look like? The bores allegedly can be reconditioned to some extent with the Sunnen AN-30 compound, some people had good results with it. I`ve never tried it. The problem with this in your case is that the pistons have a ferrous/iron coating which may have been damaged because of the seizing. This may lead to aluminum-to-aluminum (since the bore itself is is Al-Sil) contact and subsequent seizing. If you have plenty of time you may try, I`d be very curious to see how it turns out. You may end up wasting your time though.

Check out these links: https://goodson.com/products/an-30-silicon-compound
https://www.youtube.com/watch?v=TpjB0e_eaBA
911uk.com - Porsche Forum : View topic - Identifying bore scoring - with photos

You may consider Nickel Silicon Carbide plating, $750/bank.
https://www.millennium-tech.net/indService.php?id=1

The pistons seem to be OK, I'll have to do a closer inspection. I'll have a look at your links.