Very interesting accounts.
A number of aircraft took place in different tests at Farnborough; ALYU was indeed the one which blew in the testing tank, but was sufficiently intact at the end to be roaded over to the fire training school at Stansted, where it was further abused by trainee firemen for several years, finally being broken up there in 1963.
ANAV is indeed the Comet 1A aircraft passed to BOAC after the first CP aircraft crashed on delivery and they refused the second one. I never noticed it had a substantially increased seating arrangement. The nose of this aircraft is still extant, in the Science Museum store at Wroughton.
Did we link to this before ? It's a detailed account of the loss of the first CP aircraft, but contains a lot of previous and subsequent detail as well, including details of the Farnborough tests
http://www.planetofearth.com/comet-aar-march-3-1953.pdf