You could roll the dice on this one from ***********. The part number matches the one on PET for the manual mirror for a 924S, which is what it is.
FOR PORSCHE: 477857522D, 477 857 522 D - READY TO SHIP - (SIDE VIEW MIRROR)
I have them, or rather ONE, on my 924S SE- if you need me to take any measurements or anything like that PM me.