http://www.airliners.net/open.file/227404/M/
This is a link to a landing shot of N720H at KPHX just three months ago. I gather that it is a regular flier from there.
www.airliners.net is an excellent and constantly updated resource but it has no recent photos of your other queried airframes other than C-FETB shown at KPBG last August. I would take this as a fair indication that the others are no longer flying and may even be scrapped.
Have you consulted some of the better enthusiasts' publications (such as Air-Britain's) which track fleets and airframes in detail?