its my recollection that Porsche did not make an 8x15 phone dial. Only an 8x15 Fuch.
Phone dials were 6x15 and 7x15. "911/944" offsets and "928" offsets.
They did make 8x16 phone dials in both Early (which you need for an 85.2) or Late offset.
So, the OP either wants 8x15 Fuchs or comparable? (BBS, Ronal, Gotti etc)