All of this nostalgia is brilliant, and I'm a huge fan of military history. However, like bomb aimers, tail gunners, and air observers - the flight of the navigator is coming to a natural end . It's not the job people should be aspiring to when they join the RAF.
Before you bed wetting librarians start bleating on about Navs on the reaper/pred - they only took them onto it because (at the time) there were no pilots who would touch it.
There are some jobs Navs can still do, but no one respects (or trusts/listens to) a flight safety officer without wings. B&Q needs you guys - so leave with a little bit of self respect.
Maybe realise your dreams and get a PPL or something. If not there's always Microsoft Train Simulator.