"Does anyone know anything about a 55mm f1.2 Zeiss MM lens for Contax cameras?"
Yes, this lens does exist. I have a pdf file in the scan section about it. Unfortunately only text, no MTF sheet. It is an anniversary lens for the 100th anniversary of the planar design. It is a limited edition and as far as I know not produced anymore. Probably very expensive. Just look in the scan section for C/Y mount: