I dont know about the Twin Pioneers but certainly the single engined variety were shipped to the Far East by sea. When I was at RAF Seletar, 1961 to 1964 I was in the 17th Singapore Scout Group and we were gifted a "Pioneer Box" by the RAF to use as a secondary storage room and scout hut. It was basically a large box painted in a grey colour and I clearly remember it still had the shipping details stencilled on the side. I would strongly suspect that the Twins were also shipped this way as well.
I have this dated as 21/04/1962 at Speke. Maybe they were 'boxed' later, but I know for sure that this was a delivery flight.