We also had our wedding in my home country in March 2011. I did not include a copy of passport with stamp. What I included as evidence of the trip were pictures of the wedding, wedding invitation, an email copy of our flight confirmation, and boarding passes.
Hope this helps.
8/24/09 - AOS docs received in Chicago
9/04/09 - NOA's received for I-485, I-765, I-130
10/22/09 - Received EAD
11/17/09 - Interview,GC approved
11/28/09 - GC received
9/2/11 - Vermont Service Center received I-751 docs
9/9/11 - Received extension letter
10/14/11 - Biometrics Notice received, appt on 11/8/11
10/20/11 - Biometrics done (walk-in)
6/25/12 - Received letter - Approval of removal of conditions
6/30/12 - Received 10yr GC in mail