a quick Google suggests Sycamores were still at TH in '65/'66, so looks as if Herod just missed it.
Yep, The Sycamore had just been withdrawn when I started. I believe it was a quick change caused by several accidents to the old beast. My first rotary flight was 1st June '66, and I think it was one of the first courses on the Sioux. Sorry if we've caused thread drift.