Originally Posted by
treadigraph
Two registrations that have been used by more than one aircraft were G-BCSE, a CSE Learjet and Navajo; and G-BJCB, two different HS125s. Various period registrations which were either unallocated or allocated to aircraft which never flew with them were reissued to various classic imports in the 1980s, notably Luscombes. For some reason an Aerostar managed to gatecrash the party and was allocated G-ADRW...
One or two modern aircraft have managed to creep into the original 1919-1928 G-E sequence as well, for example Cessna 421 G-EAGL (geddit?) registered in 1979.
Incidentally, the CAA's G-INFO online database copes with interlopers and duplicated registrations by appending an extra 'X' on the end - so a search for the above HS125 returns G-BJCB and G-BJCBX, though of course the 'X' was never worn on the second aircraft.