Marty, the RAF had 31 with the rear loading ramp. That is the complete total that were built. 10 of those were sold to the RNZAF. There were other Andovers in RAF sevice but they were basically standard HS-748s.
I don't know of any Andovers left flying. The last ones were in Africa (ex RNZAF). I believe some of these may be still around as hulks or wrecks. I am not sure about any others on display but there must at least one in the UK.
Edit..there you go there is one at the RAF Cosford museum..its an E3 which is a converted C1 (rear loading ramp model) ...
http://en.wikipedia.org/wiki/Royal_Air_For...raft_on_displayCheck this thread out for RNZAF Andovers
http://rnzaf.proboards.com/index.cgi?board...1696&page=8Includes the fate of some of the RNZAF Andovers..Sudan, Belguim etc. There a nearly complete one still at Whenuapai (in 2011 anyway)