Originally Posted by
treadigraph
Vague recollection of several out of sequence allocations being granted before the general free for all started in the mid 1970s - G-VTOL, G-BSBH, G-BJCB plus the BOAC Concorde allocations were all quite well known, but I think there were one or two earlier examples in the 1950s/60s. Earliest was probably G-EDCA (Director of Civil Aviation, Sir William Sefton Brancker), allocated to two separate DH-60s when the G-EAAA-EBZZ sequence was allocated prior to the modern register commencing from G-AAAA in 1929.
Edit: yes, forgotten G-BSST!
I suggest G-AHDM on the Miles HDM105 (1957, originally a Halifax/Halton in 1946), plus in the more modern lot was G-BIII. There were others which were "special" but almost in sequence with the normal course of things, particularly G-AWOG for Prince William of Gloucester