500E , in my experience of other GB the life limited items on the Gearbox seldom include the housing . In most cases a full inspection and some minor reworks may be required to the housings at the first cycle, normally the parts that are replaced at each overhaul are seals and bearings. Correct me if I am wrong but the S92 was sold for it's low DOC based on the fact that all major components were on condition , was the 2700 hr TBO there from the start ?.