If you mean in personality years, Percy. By build years, probably Murdoch, as he was said to be brand new in his debut. But that again has its doubts, as the 9F's were built in the 50's and 60's, and Series 7 was not set then. Diesel 10 could be another possibility, as the Warship diesels were built right into the 70's. That's really all the help I can give you right now, I'm afraid.