That sounds like a flight time. I'm afraid that I didn't record the flight time. However, in those days we had to backtrack the runway at MPN and then turn at the end, with people with radios at the edge of the runway watching the wheels (the loop hadn't been built then). There would have been a full backtrack of the runway at ASI as well. As we obviously recorded different times, I don't think that we will ever know the answer.
EDIT; Of course the 747 is in a different FAI weight category, so the faster times wouldn't affect the record.