I've got a general question concerning 747-100s and in particular a British Airways plane: G-AWNL.
My mom dug out my 'BA Junior Jet Club' logbook form our trip to England in '77 and AWNL was one of the planes we flew on. I looked it up here and noticed in the pictures that it was modified from a 'three window' upper deck to the ten window version. I thought this was pretty interesting and would like to find out more info about this -- and if the modification included any other changes in engines etc. From the order of the pics, the mods must have taken place between 1978 and 1981.
If you know, please clue me in.