A few comments AP....
1. The rego would also be on the plate above door 1L, but it's pretty small and hard to see
2. Getting to the coughpit post docking was no issue, was none for me. I simply walked to the front, the coughpit door was open, but I asked the nearest FA politely if it would be possible to give my regards to the front office. She ducked in and asked, they said fine, and I got about 5 minutes with the lovely flight crew who even offered me to sit in the BIG CHAIR (left seat). I borrowed the observers seat (nice cushy lambswool cover
). They couldn't have been kinder with their time or words. As soon as I asked if this was their final flight and they said they had another rotation on another a/c I knew I needed to vamoose so I thanked them again so they could finish their paperwork and get onto where they needed to be.
I strongly suspect in the case of QF767 the coughpit will be an open door post docking. I would definitely think QF will understand that everyone bar those that expected to get to SYD on a normal flight will want to remain and pay their respects.