I found the Type Inspection Authorization for the DC-9 Series 80 autoland system. Included in the required conditions for the aircraft demonstration:
Conduct 100 autolands with the following wind component criteria:
1. Headwinds - At least 10% at 12.5 knots or higher with a minimum of 2 landings at 20 knots or higher.
2. Crosswinds - At least 10% at 7.5 knots or higher with a minimum of 2 landings at 12 knots or higher.
3. Tailwinds - At least 2 landings at 5 knots or higher.
It was finding these TIA required wind conditions that was difficult, not finding certification limit winds.