Just been doing some rattle sorting. Okay all doors and cupboards sorted with small strips of self-adhesive draught excluder - excellent. BUT the outside opening gas locker a real problem with loads of play so had a look at the key-locking bits. The pics below show the locking assembly before and after. The original assembly shows the swivel arm held between 2 locking washers then the locking 21mm nut. I eventually found after several trials that by re-assembling both locking washers first then reversing the locking arm followed by the locking nut the gas locker door fitted snugly but obviously still retained the 2 x 50mm square gas escape outlets.