As far as I know the Princesses were all scrapped. There's an interesting article about Saunders-Roe and the Princess in the current (April) issue of FlyPast magazine.
There is a Sunderland in the RAF Museum at Hendon. It's normally accessible to visitors so you can go on board and have a look around the inside. There's also a Sandringham (effectively a civil version of the Sunderland) at the Solent Sky museum in Southampton. I'm willing to be corrected (as always) but I don't think there is a Sunderland (or Sandringham) in flying condition anywhere in the world at the moment.
Last edited by Simtech; 13th Mar 2014 at 16:24.