What different fixed-length MU's currently exist in the UK? (Not counting classes that are due to come into service). I have 1carriage, 2carriage, 3carriage, 4carriage, 5carriage, 6carriage, 8carriage, 9carriage, 11carriage, 12carriage and 16carriage. (So not 7's - due to be on Avanti and not...