In Moscow, 1983, elderly Guy Bennett claims to be "the last of the few", two of the real Cambridge spies (Donald Maclean and Anthony Blunt) having died in that very year. In fact, the real-life model for Bennett, Guy Burgess, was the earliest of the group to die, twenty years earlier in 1963. Neither would he have been the last of the Cambridge spies still alive, since Kim Philby lived on to 1988, and John Cairncross until 1995.
When the cadets are on parade in the school quadrangle, the statue of a man in seventeenth-century dress identifies their location as the courtyard of the Bodleian Library, on the campus of Oxford University.