Sad to say there can't be many left who flew on Gomorrah, the very youngest must be 89-90 I would imagine. Still, Bomber Command aircrew are a resilient bunch, so hopefully you will find a few. On the German side Peter Spoden (Luftwaffe Nachtjager) was in contact with Martin Middlebrook some years ago, regarding several of his books. He was with his Operational Training Unit at the time of Gomorrah, he may have some information. Peter must be 93 now if he is still alive, his email address on his website is :
[email protected]. Good Luck.