The wedding presents should have been considered a move of household. Technically you should have filled out a C-3 form which would have said you were moving your stuff because of a marriage, and it would have been exempt from taxes.
Also, I am saying technically here. It would be irresponsible of me not to highlight what you are supposed to do. The worst thing that will happen is that someone will stop you by going through the green line, pull you over and look through. They will then levy duty on whatever you are bringing in that isn't excluded as personal belongings, etc.
How you prove it is older then six months is via receipts or a bill of sale for the used items.
