M104/1995 E320 ECU pin configuration identification

[Boston Benz]

Does anyone know on either the ECU itself (behind the battery) or on the wiring harness socket where pins 10 or 21 or 9 would be? Do the numbers run vertically? Horizontally. I just spent ten-minutes scrutinizing the socket and the ECY pins with a magnifying glass and LED flashlight looking for numbers of any kind. It's really hard to check continuity between the coil power wire and the ECU when you can't identify pin #10...