Update: the warranty claim was still ongoing and still no clearer on what was happening (repair or replacement). They did say it could be many weeks to resolve it all. Growing a little bored, I placed a new order (didn't realise I could have more than one), upon which Toyota called me back to say this was the best course of action and have cancelled my original order and will honour the new one.
I now have a new order incoming (arrived in UK already, wow - those Japanese factories can get stuff done quickly) and will arrive at another but different dealer closer to home. This means I won't now be proceeding with the silver GR86 on Auto Trader as I originally was going to do.
No ETA yet but expect it to be 1-2 weeks until delivery. Fingers crossed this works out better for me, I feel better getting a fresh car, just hope this one is undamaged.
PS - all colours were still available at time of finalising order.