A little bit of trivia - a friend of mine was presented with the stencil that was used to apply the registration on 83H during a visit to Faro ATC. It's now in his collection in East Sussex.
If you'd like to read about the air war and airlift in Biafra I can thoroughly recommend Michael Draper's highly detailed book 'Shadows' published by Hikoki Publications, Aldershot in 1999, ISBN 1 902109 63 5
I became involved in Hank Warton's side of the operation and met him on a number of occasions. A very likeable rogue, you might say...!
cheers
Alan