I picked one up that had had thrust lever measurement decals put next to each thrust lever.ie they had added two extra. Boeing provided two , one between 1 and 2 and the other between 3 and 4 but that wasn't good enough. Another time they had replaced a nose wheel with the incorrect speed rated tyre for the take off weight of that model 747. We were in Anthens and it took hours to get it swapped. All good fun!!!