Those are the correct station drawings for the Canadian CSR-110s & Japanese HU-16Bs, they were the last HU-16s built and were for all practical purposes identical in construction with the exception of the Tri-Phibian mode for the Canadian aircraft. About half of the CSR-110s were built to be Tri-Phibians with the addition of a retractable hull ski mounted on the keel and removable outrider stabilizers on the tips of the floats. The earliest CSR-110s had an external hull ski, this was later modified to fit flush with the rest of the keel. It is distinguishable by a notch sometimes seen in profile photos. All of the CSR-110s had the late tip floats with the Tri-Phibian outrigger mounting, this was standard on all HU-16s leaving the factory from the late 1950s. The first image shows the early external keel, all the others show the built in keel.