Yeah, looked into that question myself and found the date of delivery to be 18.May 1989. Given that this incidence took place a good many years ago it could be that I'm somewhat off on the time-line as I've have had to base that on what projects I was engaged then. Your info has made me look into the time-line a bit more thoroughly and I now find it likely that the described incident took place sometime in Feb-Mar 1990.
At the time the aircraft felt brand new with its, then ultramodern, winglets. It was definitely an upgrade over the older 747 (assuming that was a 200 as it was not a 300-combo) that brought us from Amsterdam to Houston two weeks prior.