Regarding the Sandringham at Solentsky Museum in Southampton, UK, I flew as a passenger in that flying-boat back in 1974. It is a Sandringham Mk.4 that was originally rebuilt from a Sunderland Mk.III by Shorts & Harland of Belfast for Tasman Empire Airways Ltd (TEAL), now Air New Zealand, in 1947 for service on the trans-Tasman Auckland-Sydney route. In 1950, TEAL sold the Sandringham to Barrier Reef Airways in Australia, then it eventually passed to BRA's parent company, Ansett who operated it on the Sydney-Lord Howe Island route. In 1974 when I was living in Sydney, Ansett flew several non-scheduled flights to mark the end of their flying-boat services and I (along with a couple of friends) went on one of those flights. We flew to a lake a couple of hours inland from Sydney (although I cannot remember the name of the lake all these years later) and after landing on the lake and being taken ashore by boat for lunch at a local hotel, we reboarded the Sandringham and flew back to Rose Bay, Sydney. I remember Ansett had a second flying-boat, a Sunderland Mk.5 that they had purchased from the RNZAF and converted into an airliner. I understand that is the Sunderland that is now owned by Kermit Weeks in Florida.
There is also an ex-RNZAF Sunderland Mk.5 in pieces on the Chatham Islands (east of New Zealand), that the locals are trying to put back together for display purposes. See the following thread at another messageboard.....
Wings Over New Zealand - Chatham Island Sunderland - recent photos