First off, I would like to say that I am so very happy to have found this forum just recently. Thanks to everyone for all the helpful pieces of information!
I have read many posts with people in similar situation but mine (as usual) is rather different, so please bare with me and I do really hope someone can point me in the right direction.
I will try to make it short:
a) am a wife (US citizen) of a German national, both of us working full time and living here for over a year now
b) In mid January I have received the EEA 5-year residency card stamped in my passport.
c) Was living happily ever after, until I had to send my US passport to a bank as proof of i.d. mid June. They have received it. But it has now been LOST on its way back to me, officially declared so yesterday.
We have got a trip planned to Berlin on the 29th, so in a week. I cannot reschedule it. I can't describe to you the sleepless nights and the stressful days I have had this week, dealing with the bank and the Royal mail. I would like to see if I can fly with him to Berlin and come back semi-smoothly in to the Uk (coming back August 2nd).
I am due for a passport appointment in the US consulate in London Tuesday, where I was told I can be issued an emergency travel passport. As I am a non-visa national, I should be allowed by the airline to board, right? Germany should let me in also relatively problem-free.
If we arm ourselves with our marriage certificate, copy of old passport, work contracts, council tax papers and flat leases, as well as copies of pertinent legal support, surely they cannot turn me away at the border on Aug 2nd?! I also have the cover letter with me which came together with my EEA residence card in January, stating I can live an work in the Uk, so surely that can be very helpful and they must be able to see it in their system?
We are in Berlin for only 4 days, and I will be on an emergency passport, so I do not have the option to apply for the 6 month EEA permit from there.
I have found a legal precedent online which seems to support my case. This is the EU Court ruling from 2002, Case of Mrax vs. Belgium
"a Member State maynot send back at the border a third country national who ismarried to a national of a Member State and attempts to enterits territory without being in possession of a valid identity card
or passport or, if necessary, a visa, where he is able to prove his
identity and the conjugal ties and there is no evidence to
establish that he represents a risk to the requirements of public
policy, public security or public health within the meaning of
Article 10 of Directive 68/360 and Article 8 of Directive 73/"
Sorry this is slightly long

I would be so grateful for your thoughts and advice!!
Thanks in advance