Yes, IXRC wheels is what I am after. I have the factory Tequipment catalogs and the Porsche NA order guides showing it as factory orderable instead of dealer accessory only. I went down the same rabbit hole as you and am trying to find a window sticker with IXRB or IXRC on it.
In other news, I did procure a replacement factory wheel for now:
https://youtu.be/tn1XmBwe4tc