What I found curious was the degree of apparent cannibalisation of some of the BA 747s. One, for example (photo 14/22), was missing four of its starboard doors. Might that have been due to a quick sale to an airline needing quick replacements for an aircraft where the slides had been used? There are others where the spoilers, winglets and other bits and pieces have been removed. I wonder how large an industry recycling is.
Edit: answering my own question, "rather large" might fit. Googled "aircraft recycling" and first up was "Aircraft Fleet Recycling Association, AFRA". Now, when I need a set of DC-3 passenger seats complete with ashtrays, I know where to go....